Necrotizing Fasciitis (Clinical)

Overview

Epidemiology^[1,15]

• Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency:  0.3–15 cases per 100,000/year
• 20%–40% of affected individuals have diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus.
• Men to women ratio: 3:1
• Mortality Mortality All deaths reported in a given population. Measures of Health Status: 20%–80%
• Areas most commonly affected: anterior abdominal wall Abdominal wall The outer margins of the abdomen, extending from the osteocartilaginous thoracic cage to the pelvis. Though its major part is muscular, the abdominal wall consists of at least seven layers: the skin, subcutaneous fat, deep fascia; abdominal muscles, transversalis fascia, extraperitoneal fat, and the parietal peritoneum. Surgical Anatomy of the Abdomen, perineum Perineum The body region lying between the genital area and the anus on the surface of the trunk, and to the shallow compartment lying deep to this area that is inferior to the pelvic diaphragm. The surface area is between the vulva and the anus in the female, and between the scrotum and the anus in the male. Vagina, Vulva, and Pelvic Floor: Anatomy, scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy, extremities

Etiology^{[1,3,4, 8,11,13]}

Necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis is divided into microbiologic categories based on the causative organism(s):

• Type I:
  • Polymicrobial infection containing anaerobes Anaerobes Lincosamides and aerobes:
    • Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus pyogenes
    • Bacteroides Bacteroides Bacteroides is a genus of opportunistic, anaerobic, gram-negative bacilli. Bacteroides fragilis is the most common species involved in human disease and is part of the normal flora of the large intestine. Bacteroides
    • Peptostreptococcus Peptostreptococcus A genus of gram-positive, anaerobic, coccoid bacteria that is part of the normal flora of humans. Its organisms are opportunistic pathogens causing bacteremias and soft tissue infections. Perianal and Perirectal Abscess
    • Escherichia coli Escherichia coli The gram-negative bacterium Escherichia coli is a key component of the human gut microbiota. Most strains of E. coli are avirulent, but occasionally they escape the GI tract, infecting the urinary tract and other sites. Less common strains of E. coli are able to cause disease within the GI tract, most commonly presenting as abdominal pain and diarrhea. Escherichia coli
    • Enterobacter Enterobacter Multidrug-resistant Organisms and Nosocomial Infections
    • Klebsiella Klebsiella Klebsiella are encapsulated gram-negative, lactose-fermenting bacilli. They form pink colonies on MacConkey agar due to lactose fermentation. The main virulence factor is a polysaccharide capsule. Klebsiella pneumoniae is the most important pathogenic species. Klebsiella
    • Proteus Proteus Proteus spp. are gram-negative, facultatively anaerobic bacilli. Different types of infection result from Proteus, but the urinary tract is the most common site. The majority of cases are caused by Proteus mirabilis (P. mirabilis). The bacteria are part of the normal intestinal flora and are also found in the environment. Proteus
  • Often seen in older adults with comorbidities Comorbidities The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival. St. Louis Encephalitis Virus, particularly diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus
  • Most common type
• Type II:
  • Monomicrobial infection:
    • Group A Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus (most common)
    • Staphylococcus aureus Staphylococcus aureus Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications. Brain Abscess (including MRSA MRSA A strain of Staphylococcus aureus that is non-susceptible to the action of methicillin. The mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins. Staphylococcus)
  • Occurs in any age group
  • Frequently found in individuals with no significant risk factors
• Type III:
  • Marine/aquatic gram-negative organisms
  • Vibrio vulnificus Vibrio vulnificus A species of halophilic bacteria in the genus vibrio, which lives in warm seawater. It can cause infections in those who eat raw contaminated seafood or have open wounds exposed to seawater. Vibrio
    • From aquatic injuries or consumption of raw seafood
    • More often seen in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with chronic liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy disease
  • Aeromonas hydrophila Aeromonas hydrophila A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that may be pathogenic for frogs, fish, and mammals, including man. In humans, cellulitis and diarrhea can result from infection with this organism. Cellulitis: from freshwater exposure through a laceration Laceration Torn, ragged, mangled wounds. Blunt Chest Trauma
  • Gas gangrene Gangrene Death and putrefaction of tissue usually due to a loss of blood supply. Small Bowel Obstruction (treated as a distinct entity by others)
    • Most commonly from traumatic inoculation with Clostridium perfringens Clostridium perfringens The most common etiologic agent of gas gangrene. It is differentiable into several distinct types based on the distribution of twelve different toxins. Gas Gangrene
    • Clostridium septicum Clostridium septicum A species of gram-positive bacteria in the family clostridiaceae. Infections have a strong association with malignancies and also with gas gangrene. Gas Gangrene is linked with colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy cancer and leukemia.
• Type IV
  • Fungal  infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease, mainly  Candida Candida Candida is a genus of dimorphic, opportunistic fungi. Candida albicans is part of the normal human flora and is the most common cause of candidiasis. The clinical presentation varies and can include localized mucocutaneous infections (e.g., oropharyngeal, esophageal, intertriginous, and vulvovaginal candidiasis) and invasive disease (e.g., candidemia, intraabdominal abscess, pericarditis, and meningitis). Candida/Candidiasis and Zygomycetes/mucormycetes
  • Seen in  immunocompromised immunocompromised A human or animal whose immunologic mechanism is deficient because of an immunodeficiency disorder or other disease or as the result of the administration of immunosuppressive drugs or radiation. Gastroenteritis hosts

Risk factors^{[1,2,4,8,9,11,14]}

• Immunosuppression:
  • Diabetes Diabetes Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and dysfunction of the regulation of glucose metabolism by insulin. Type 1 DM is diagnosed mostly in children and young adults as the result of autoimmune destruction of β cells in the pancreas and the resulting lack of insulin. Type 2 DM has a significant association with obesity and is characterized by insulin resistance. Diabetes Mellitus mellitus (most common predisposing condition)
  • HIV HIV Anti-HIV Drugs
  • Neutropenia Neutropenia Neutrophils are an important component of the immune system and play a significant role in the eradication of infections. Low numbers of circulating neutrophils, referred to as neutropenia, predispose the body to recurrent infections or sepsis, though patients can also be asymptomatic. Neutropenia
• Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions damage:
  • Major penetrating trauma or minor laceration Laceration Torn, ragged, mangled wounds. Blunt Chest Trauma 
  • Intravenous drug use disorder
  • Recent surgery
  • Insect bite
• Malignancy Malignancy Hemothorax
• Obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity
• Smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases
• Alcoholism Alcoholism A primary, chronic disease with genetic, psychosocial, and environmental factors influencing its development and manifestations. The disease is often progressive and fatal. It is characterized by impaired control over drinking, preoccupation with the drug alcohol, use of alcohol despite adverse consequences, and distortions in thinking, most notably denial. Each of these symptoms may be continuous or periodic. Wernicke Encephalopathy and Korsakoff Syndrome 
• Liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy cirrhosis Cirrhosis Cirrhosis is a late stage of hepatic parenchymal necrosis and scarring (fibrosis) most commonly due to hepatitis C infection and alcoholic liver disease. Patients may present with jaundice, ascites, and hepatosplenomegaly. Cirrhosis can also cause complications such as hepatic encephalopathy, portal hypertension, portal vein thrombosis, and hepatorenal syndrome. Cirrhosis
• Chronic cardiac disease
• Chronic renal failure Renal failure Conditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate. Crush Syndrome
• Peripheral vascular disease
• Advanced age
• Malnutrition Malnutrition Malnutrition is a clinical state caused by an imbalance or deficiency of calories and/or micronutrients and macronutrients. The 2 main manifestations of acute severe malnutrition are marasmus (total caloric insufficiency) and kwashiorkor (protein malnutrition with characteristic edema). Malnutrition in children in resource-limited countries

Pathophysiology^{[1,2,7,8,11,14]}

• Routes:
  • Bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology extend into the subcutaneous tissue Subcutaneous tissue Loose connective tissue lying under the dermis, which binds skin loosely to subjacent tissues. It may contain a pad of adipocytes, which vary in number according to the area of the body and vary in size according to the nutritional state. Soft Tissue Abscess from:
    • Defined portal of entry:
      • Nearby ulcer or superficial infection
      • Trauma
    • Bloodstream (most often S. pyogenes, seeding Seeding The local implantation of tumor cells by contamination of instruments and surgical equipment during and after surgical resection, resulting in local growth of the cells and tumor formation. Grading, Staging, and Metastasis a site of deep, non-penetrating injury via transient bacteremia Bacteremia The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion. Glycopeptides, frequently from asymptomatic pharyngeal carriage)
  • Even in monomicrobial infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease, other aerobic and anaerobic pathogens may play a role.
• Toxin-mediated destruction:
  • Fulminant inflammatory response occurs, affecting tissues and vessels, causing microvascular thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus then tissue destruction follows.
  • In Group A streptococcal disease: streptolysin O leads to platelet-neutrophil aggregrates obstructing vessels.
  • Infection causes occlusion of subcutaneous capillaries Capillaries Capillaries are the primary structures in the circulatory system that allow the exchange of gas, nutrients, and other materials between the blood and the extracellular fluid (ECF). Capillaries are the smallest of the blood vessels. Because a capillary diameter is so small, only 1 RBC may pass through at a time. Capillaries: Histology, venules Venules The minute vessels that collect blood from the capillary plexuses and join together to form veins. Veins: Histology, and arterioles Arterioles The smallest divisions of the arteries located between the muscular arteries and the capillaries. Arteries: Histology → tissue and fascial ischemia Ischemia A hypoperfusion of the blood through an organ or tissue caused by a pathologic constriction or obstruction of its blood vessels, or an absence of blood circulation. Ischemic Cell Damage → progressive thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus → necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage
    • Damage occurs to superficial nerves → localized anesthesia Anesthesia A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures. Anesthesiology: History and Basic Concepts
    • Hypoxic conditions → ↓ neutrophil function → proliferation of bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology
• Fascial spread:
  • Infection and necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage can rapidly travel along fascial planes, possibly due to bacterial enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes and toxins.
  • Streptococcal enzymes Enzymes Enzymes are complex protein biocatalysts that accelerate chemical reactions without being consumed by them. Due to the body’s constant metabolic needs, the absence of enzymes would make life unsustainable, as reactions would occur too slowly without these molecules. Basics of Enzymes/toxins that drive fascial spread:
    • Hyaluronidase Hyaluronidase Bacteroides: degrades connective tissue Connective tissue Connective tissues originate from embryonic mesenchyme and are present throughout the body except inside the brain and spinal cord. The main function of connective tissues is to provide structural support to organs. Connective tissues consist of cells and an extracellular matrix. Connective Tissue: Histology ground substance Ground substance Connective Tissue: Histology
    • Streptolysin and proteases Proteases Proteins and Peptides: lead to tissue liquefaction
    • Streptococcal pyrogenic exotoxins Pyrogenic Exotoxins Scarlet Fever (notably from M1/M3 serotypes): superantigens Superantigens Microbial antigens that have in common an extremely potent activating effect on T-cells that bear a specific variable region. Superantigens cross-link the variable region with class II mhc proteins regardless of the peptide binding in the t-cell receptor’s pocket. The result is a transient expansion and subsequent death and anergy of the T-cells with the appropriate variable regions. Staphylococcus that drive the cytokine cascade, leading to multiorgan failure, and the streptococcal toxic shock syndrome Streptococcal Toxic Shock Syndrome Toxic Shock Syndrome
• Gas formation:
  • Aerobic metabolism produces water-soluble CO₂.
  • Anaerobic metabolism by facultative organisms → hydrogen, and poorly-soluble gases
    • Hydrogen and nitrogen Nitrogen An element with the atomic symbol n, atomic number 7, and atomic weight [14. 00643; 14. 00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth’s atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells. Urea Cycle are insoluble and accumulate in the subcutaneous tissues.
    • Seen as gas in imaging
    • In clostridial gas gangrene Gangrene Death and putrefaction of tissue usually due to a loss of blood supply. Small Bowel Obstruction, C. perfringens C. perfringens The most common etiologic agent of gas gangrene. It is differentiable into several distinct types based on the distribution of twelve different toxins. Gas Gangrene alpha-toxin Alpha-Toxin Gas Gangrene ( phospholipase C Phospholipase C A subclass of phospholipases that hydrolyze the phosphoester bond found in the third position of glycerophospholipids. Although the singular term phospholipase C specifically refers to an enzyme that catalyzes the hydrolysis of phosphatidylcholine, it is commonly used in the literature to refer to broad variety of enzymes that specifically catalyze the hydrolysis of phosphatidylinositols. Pseudomonas) and other exotoxins Exotoxins Toxins produced, especially by bacterial or fungal cells, and released into the culture medium or environment. Bacteriology drives gas production leading to myonecrosis Myonecrosis A severe condition resulting from bacteria invading healthy muscle from adjacent traumatized muscle or soft tissue. The infection originates in a wound contaminated with bacteria of the genus Clostridium. C. perfringens accounts for the majority of cases (over eighty percent), while C. novyi, C. septicum, and C. histolyticum cause most of the other cases. Clostridia.

Clinical Presentation

Skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions and soft tissue Soft Tissue Soft Tissue Abscess findings^[1,8,11]

Be sure to mark skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions lesions during the physical examination.

Early signs:

• Acute, severe pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways out of proportion with physical findings
• Erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion that quickly spreads over hours to days.
• Warmth
• Tense, indurated skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions

Late signs:

• Crepitus Crepitus Osteoarthritis
• Anesthesia Anesthesia A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures. Anesthesiology: History and Basic Concepts or paresthesia
• Bullae Bullae Erythema Multiforme, skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions ecchymosis Ecchymosis Extravasation of blood into the skin, resulting in a nonelevated, rounded or irregular, blue or purplish patch, larger than a petechia. Orbital Fractures, edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema outside of the area of erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion, skin necrosis Skin Necrosis Rocky Mountain Spotted Fever, or ulceration Ulceration Corneal Abrasions, Erosion, and Ulcers

Common sites of infection:

• Extremities (most common)  > trunk > perineum Perineum The body region lying between the genital area and the anus on the surface of the trunk, and to the shallow compartment lying deep to this area that is inferior to the pelvic diaphragm. The surface area is between the vulva and the anus in the female, and between the scrotum and the anus in the male. Vagina, Vulva, and Pelvic Floor: Anatomy > head/ neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess
• Fournier gangrene Fournier gangrene An acute necrotic infection of the scrotum; penis; or perineum. It is characterized by scrotum pain and redness with rapid progression to gangrene and sloughing of tissue. Fournier gangrene is usually secondary to perirectal or periurethral infections associated with local trauma, operative procedures, or urinary tract disease. Necrotizing Fasciitis ( necrotizing fasciitis of the perineum Necrotizing fasciitis of the perineum An acute necrotic infection of the scrotum; penis; or perineum. It is characterized by scrotum pain and redness with rapid progression to gangrene and sloughing of tissue. Fournier gangrene is usually secondary to perirectal or periurethral infections associated with local trauma, operative procedures, or urinary tract disease. Necrotizing Fasciitis):
  • Presents as pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, redness Redness Inflammation, and swelling Swelling Inflammation in the genital area
  • Rapidly spreads to the anterior abdominal wall Abdominal wall The outer margins of the abdomen, extending from the osteocartilaginous thoracic cage to the pelvis. Though its major part is muscular, the abdominal wall consists of at least seven layers: the skin, subcutaneous fat, deep fascia; abdominal muscles, transversalis fascia, extraperitoneal fat, and the parietal peritoneum. Surgical Anatomy of the Abdomen and gluteal muscles
• Head and neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess:
  • Often has a dental or pharyngeal origin from procedures or trauma
  • May spread to the face, lower neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess, and mediastinum Mediastinum The mediastinum is the thoracic area between the 2 pleural cavities. The mediastinum contains vital structures of the circulatory, respiratory, digestive, and nervous systems including the heart and esophagus, and major thoracic vessels. Mediastinum and Great Vessels: Anatomy

Evidence of systemic toxicity Toxicity Dosage Calculation^[8,11]

• High fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
• Tachycardia Tachycardia Abnormally rapid heartbeat, usually with a heart rate above 100 beats per minute for adults. Tachycardia accompanied by disturbance in the cardiac depolarization (cardiac arrhythmia) is called tachyarrhythmia. Sepsis in Children
• Hypotension Hypotension Hypotension is defined as low blood pressure, specifically < 90/60 mm Hg, and is most commonly a physiologic response. Hypotension may be mild, serious, or life threatening, depending on the cause. Hypotension 
• Altered mentation:
  • Confusion
  • Obtundation

Diagnosis

A definitive diagnosis of necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis is made by surgical exploration and debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome. These processes should not be delayed to obtain diagnostic information, if the clinical suspicion is high.

However, the following may be helpful:

Laboratory evaluation^[5,6,10,14]

Laboratory studies may demonstrate evidence of infection and organ damage.

• Gram stain Gram stain Klebsiella and cultures should be obtained from:
  • Blood (preferably before antibiotics are given)
  • Intraoperative specimens 
• ↑ WBC with left shift Left Shift Yersinia pestis/Plague
• ↑ Erythrocyte sedimentation rate Erythrocyte Sedimentation Rate Soft Tissue Abscess and c-reactive proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis
• ↓ HCO₃ → metabolic acidosis Acidosis A pathologic condition of acid accumulation or depletion of base in the body. The two main types are respiratory acidosis and metabolic acidosis, due to metabolic acid build up. Respiratory Acidosis
• ↑ Lactic acid 
• ↑ Blood urea Urea A compound formed in the liver from ammonia produced by the deamination of amino acids. It is the principal end product of protein catabolism and constitutes about one half of the total urinary solids. Urea Cycle nitrogen Nitrogen An element with the atomic symbol n, atomic number 7, and atomic weight [14. 00643; 14. 00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth’s atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells. Urea Cycle and creatinine → acute renal failure Renal failure Conditions in which the kidneys perform below the normal level in the ability to remove wastes, concentrate urine, and maintain electrolyte balance; blood pressure; and calcium metabolism. Renal insufficiency can be classified by the degree of kidney damage (as measured by the level of proteinuria) and reduction in glomerular filtration rate. Crush Syndrome
• ↑ Glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance
• ↓ Na
• ↑ CK, and/or AST AST Enzymes of the transferase class that catalyze the conversion of l-aspartate and 2-ketoglutarate to oxaloacetate and l-glutamate. Liver Function Tests → indicative of deep infection involving muscle/ fascia Fascia Layers of connective tissue of variable thickness. The superficial fascia is found immediately below the skin; the deep fascia invests muscles, nerves, and other organs. Cellulitis (vs cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis)
• ↑ Procalcitonin Procalcitonin Neutropenic Fever on admission → increased risk of septic shock Septic shock Sepsis associated with hypotension or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to lactic acidosis; oliguria; or acute alteration in mental status. Sepsis and Septic Shock

Note: lactate >6 mmol/L and a serum Na <135 mEq/L on admission are independent predictors of in-hospital mortality Mortality All deaths reported in a given population. Measures of Health Status (in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship presenting with necrotizing soft tissue Soft Tissue Soft Tissue Abscess infection).

Laboratory Risk Indicator Indicator Methods for assessing flow through a system by injection of a known quantity of an indicator, such as a dye, radionuclide, or chilled liquid, into the system and monitoring its concentration over time at a specific point in the system. Body Fluid Compartments for Necrotizing Fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis (LRINEC) Score^[5,6,8,9]

• Calculator
• Calculates a score using WBC, c-reactive protein, hemoglobin, creatinine, sodium Sodium A member of the alkali group of metals. It has the atomic symbol na, atomic number 11, and atomic weight 23. Hyponatremia, and glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance
• Has a high specificity but low sensitivity
• Should not be used alone to rule out infection; if clinical suspicion is high, consult surgery regardless of the score.
• Score ≥ 6 is highly suggestive of necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis.

Imaging^[6,8,9,14]

Imaging may be needed to assist in the diagnosis, especially if there is uncertainty.

• CT scan is the best imaging modality and may show:
  • Subcutaneous gas 
  • Inflammatory changes along fascial planes
  • Fluid collections
  • In contrast-enahnced CT: no fascial enhancement in thickened soft-tissue fascia Fascia Layers of connective tissue of variable thickness. The superficial fascia is found immediately below the skin; the deep fascia invests muscles, nerves, and other organs. Cellulitis (most specific finding)
• MRI is an alternative:
  • Most sensitive test overall
  • Costly and time-consuming (not recommended if clinical suspicion is high, as this could delay surgical intervention)
  • Finding: T2 hyperintensity of deep fascia Fascia Layers of connective tissue of variable thickness. The superficial fascia is found immediately below the skin; the deep fascia invests muscles, nerves, and other organs. Cellulitis
• Ultrasonography:
  • Can be performed rapidly
  • Requires skilled technician
  • Finding: fascial plane fluid accumulation, subcutaneous emphysema Subcutaneous emphysema Presence of air or gas in the subcutaneous tissues of the body. Mallory-Weiss Syndrome (Mallory-Weiss Tear); can identify abscesses
• Radiography:
  • Can reveal gas in the tissues, particularly in the extremities
  • Cannot rule out necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis

Other tests^[6,8]

The following may be used as complementary exams in cases where the diagnosis is uncertain:

Finger test:

• 2-cm excision made at bedside under local anesthesia Anesthesia A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures. Anesthesiology: History and Basic Concepts
• Wound explored bluntly with a gloved finger
• Findings of necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis:
  • “Dishwater pus” (thin grayish fluid)
  • Absence of bleeding
  • No tissue resistance Resistance Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow. Ventilation: Mechanics of Breathing to finger dissection

Frozen-section biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma: 

• Obtained during finger test or operative exploration
• Tissue sent for:
  • Histologic evaluation
  • Gram stain Gram stain Klebsiella
  • Culture
• Can provide quick diagnosis confirmation, if in doubt

Management

Management of necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis has slight variations depending on practice location.  The following information was derived from US and UK literature and clinical guidelines. Overall, therapy should be guided by a multidisciplinary team, including surgery, intensive care, and infectious disease specialists.^[8]

Surgery

Emergent surgical debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome is the mainstay of treatment.

Timing:^[4,6‒9,14]

• Surgery must be performed as early as possible, preferably in the 1st 6 hours.
  • Delay beyond the 1st 24 hours or restricted primary debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome are associated with significantly increased mortality Mortality All deaths reported in a given population. Measures of Health Status.
  • Debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome should aim to remove devitalized tissue as completely as possible; should extend to healthy, bleeding, contractile tissue
  • Microbiology/tissue samples are taken during the procedure.
• Surgical exploration is also the diagnostic gold standard:
  • Warranted whenever clinical suspicion is high
  • Intraoperative findings include:
    • Dishwater-gray pus/ exudate Exudate Exudates are fluids, cells, or other cellular substances that are slowly discharged from blood vessels usually from inflamed tissues. Pleural Effusion
    • Non-contracting muscle (dull and opaque)
    • Lack of bleeding due to microvascular thrombosis Thrombosis Formation and development of a thrombus or blood clot in the blood vessel. Epidemic Typhus
    • Positive “finger test” (no tissue resistance Resistance Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow. Ventilation: Mechanics of Breathing; tissues easily separated by a gloved finger)
• Surgical debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome frequently needs to be repeated over the next 24–48 hours:
  • “2nd-look operation” to reevaluate tissue viability and spread of infection
  • Sometimes, multiple serial debridements need to be performed. 
• In case of wide or disfiguring debridements, involve additional teams:
  • Urology for wounds involving the perineum Perineum The body region lying between the genital area and the anus on the surface of the trunk, and to the shallow compartment lying deep to this area that is inferior to the pelvic diaphragm. The surface area is between the vulva and the anus in the female, and between the scrotum and the anus in the male. Vagina, Vulva, and Pelvic Floor: Anatomy, penis Penis The penis is the male organ of copulation and micturition. The organ is composed of a root, body, and glans. The root is attached to the pubic bone by the crura penis. The body consists of the 2 parallel corpora cavernosa and the corpus spongiosum. The glans is ensheathed by the prepuce or foreskin. Penis: Anatomy or scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy
  • Plastic surgery for complex reconstruction or muscle flap reconstruction
  • Orthopedics for infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease with bony involvement

Technical considerations:^[6]

• Incisions performed parallel to Langer’s lines to promote healing and minimize scarring Scarring Inflammation
• Wounds left open to heal by secondary intention Secondary intention When there are significant tissue losses and the wound surface cannot be brought together (e.g., lacerations, burns, and ulcers) Wound Healing and/or drains inserted to promote continuous drainage of infection
• Wound Vac therapy frequently used to promote wound healing Wound healing Wound healing is a physiological process involving tissue repair in response to injury. It involves a complex interaction of various cell types, cytokines, and inflammatory mediators. Wound healing stages include hemostasis, inflammation, granulation, and remodeling. Wound Healing
• Important to note:
  • Wound Vac is delayed until the wound is stable and debridements are done.
  • Use with extreme caution in anaerobic infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease; the closed, oxygen-deprived environment may exacerbate anaerobic growth.

Anatomical considerations:^[6]

• Abdominal wall Abdominal wall The outer margins of the abdomen, extending from the osteocartilaginous thoracic cage to the pelvis. Though its major part is muscular, the abdominal wall consists of at least seven layers: the skin, subcutaneous fat, deep fascia; abdominal muscles, transversalis fascia, extraperitoneal fat, and the parietal peritoneum. Surgical Anatomy of the Abdomen:
  • Explored in a longitudinal direction
  • Infection may spread to bowels and cause peritonitis Peritonitis Inflammation of the peritoneum lining the abdominal cavity as the result of infectious, autoimmune, or chemical processes. Primary peritonitis is due to infection of the peritoneal cavity via hematogenous or lymphatic spread and without intra-abdominal source. Secondary peritonitis arises from the abdominal cavity itself through rupture or abscess of intra-abdominal organs. Penetrating Abdominal Injury and require exploratory laparotomy Exploratory Laparotomy Laparotomy and Laparoscopy
• Fournier’s gangrene Gangrene Death and putrefaction of tissue usually due to a loss of blood supply. Small Bowel Obstruction:
  • May involve scrotum Scrotum A cutaneous pouch of skin containing the testicles and spermatic cords. Testicles: Anatomy, inguinal regions, and lower abdominal wall Abdominal wall The outer margins of the abdomen, extending from the osteocartilaginous thoracic cage to the pelvis. Though its major part is muscular, the abdominal wall consists of at least seven layers: the skin, subcutaneous fat, deep fascia; abdominal muscles, transversalis fascia, extraperitoneal fat, and the parietal peritoneum. Surgical Anatomy of the Abdomen
  • May require orchiectomy, cystectomy, and diverting colostomy depending on extent 
• Extremities:
  • Fasciotomies may be required.
  • Amputation Amputation An amputation is the separation of a portion of the limb or the entire limb from the body, along with the bone. Amputations are generally indicated for conditions that compromise the viability of the limb or promote the spread of a local process that could manifest systemically. Amputation may be necessary with muscle involvement, rapidly spreading infection, vascular compromise, or severe shock Shock Shock is a life-threatening condition associated with impaired circulation that results in tissue hypoxia. The different types of shock are based on the underlying cause: distributive (↑ cardiac output (CO), ↓ systemic vascular resistance (SVR)), cardiogenic (↓ CO, ↑ SVR), hypovolemic (↓ CO, ↑ SVR), obstructive (↓ CO), and mixed. Types of Shock.
• Axilla Axilla The axilla is a pyramid-shaped space located between the upper thorax and the arm. The axilla has a base, an apex, and 4 walls (anterior, medial, lateral, posterior). The base of the pyramid is made up of the axillary skin. The apex is the axillary inlet, located between the 1st rib, superior border of the scapula, and clavicle. Axilla and Brachial Plexus: Anatomy:
  • Infection may spread rapidly along lymphatics and blood vessels
  • Early debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome is paramount

Antibiotic therapy

In the US, an initial therapy regimen should include each of the following categories:^[4,6–9,14]

• Broad-spectrum Broad-Spectrum Fluoroquinolones coverage (1 of the following):
  • Carbapenems Carbapenems A group of beta-lactam antibiotics in which the sulfur atom in the thiazolidine ring of the penicillin molecule is replaced by a carbon atom. Thienamycins are a subgroup of carbapenems which have a sulfur atom as the first constituent of the side chain. Carbapenems and Aztreonam
  • Piperacillin Piperacillin Semisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics. Penicillins– tazobactam Tazobactam A penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria. Cephalosporins
  • Ceftriaxone Ceftriaxone A broad-spectrum cephalosporin antibiotic and cefotaxime derivative with a very long half-life and high penetrability to meninges, eyes and inner ears. Cephalosporins (or cefotaxime Cefotaxime Semisynthetic broad-spectrum cephalosporin. Cephalosporins) plus metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess
• MRSA MRSA A strain of Staphylococcus aureus that is non-susceptible to the action of methicillin. The mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins. Staphylococcus coverage (1 of the following):
  • Vancomycin Vancomycin Antibacterial obtained from streptomyces orientalis. It is a glycopeptide related to ristocetin that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear. Glycopeptides 
  • Daptomycin Daptomycin A cyclic lipopeptide antibiotic that inhibits gram-positive bacteria. Lipopeptides and Lipoglycopeptides 
  • Linezolid Linezolid An oxazolidinone and acetamide derived anti-bacterial agent and protein synthesis inhibitor that is used in the treatment of gram-positive bacterial infections of the skin and respiratory tract. Oxazolidinones (also has antitoxin effect)
• For antitoxin effects against toxin-producing streptococci or staphylococci: clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides (if linezolid Linezolid An oxazolidinone and acetamide derived anti-bacterial agent and protein synthesis inhibitor that is used in the treatment of gram-positive bacterial infections of the skin and respiratory tract. Oxazolidinones is given, clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides would not be needed)

In the UK:^[11,12]

• Regimens may vary greatly depending on the National Health Service (NHS) trust Trust Confidence in or reliance on a person or thing. Conflict of Interest hospital (see local guidelines).
• An example of an initial therapy regimen for broad coverage may include:
  • Flucloxacillin
  • Benzylpenicillin
  • Metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess
  • Clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides
  • Gentamicin Gentamicin Aminoglycosides
• If MRSA MRSA A strain of Staphylococcus aureus that is non-susceptible to the action of methicillin. The mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins. Staphylococcus suspected (or beta-lactam Beta-Lactam Penicillins allergy Allergy An abnormal adaptive immune response that may or may not involve antigen-specific IgE Type I Hypersensitivity Reaction) → replace flucloxacillin and benzylpenicillin with vancomycin Vancomycin Antibacterial obtained from streptomyces orientalis. It is a glycopeptide related to ristocetin that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear. Glycopeptides or linezolid Linezolid An oxazolidinone and acetamide derived anti-bacterial agent and protein synthesis inhibitor that is used in the treatment of gram-positive bacterial infections of the skin and respiratory tract. Oxazolidinones
• Other example regimens by type:^[13]
  • Type I: piperacillin Piperacillin Semisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics. Penicillins– tazobactam Tazobactam A penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria. Cephalosporins (or meropenem Meropenem A thienamycin derivative antibacterial agent that is more stable to renal dehydropeptidase I than imipenem, but does not need to be given with an enzyme inhibitor such as cilastatin. It is used in the treatment of bacterial infections, including infections in immunocompromised patients. Carbapenems and Aztreonam) + clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides
  • Type II: benzylpenicillin (or ceftriaxone Ceftriaxone A broad-spectrum cephalosporin antibiotic and cefotaxime derivative with a very long half-life and high penetrability to meninges, eyes and inner ears. Cephalosporins or ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones) + clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides

Therapy should eventually be tailored to culture data and local resistance Resistance Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow. Ventilation: Mechanics of Breathing patterns (when available) → examples:^[6,7,9]

• Streptococcus Streptococcus Streptococcus is one of the two medically important genera of gram-positive cocci, the other being Staphylococcus. Streptococci are identified as different species on blood agar on the basis of their hemolytic pattern and sensitivity to optochin and bacitracin. There are many pathogenic species of streptococci, including S. pyogenes, S. agalactiae, S. pneumoniae, and the viridans streptococci. Streptococcus: penicillin Penicillin Rheumatic Fever + clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides
• MSSA: penicillins Penicillins Beta-lactam antibiotics contain a beta-lactam ring as a part of their chemical structure. Drugs in this class include penicillin G and V, penicillinase-sensitive and penicillinase-resistant penicillins, cephalosporins, carbapenems, and aztreonam. Penicillins or cephalosporins Cephalosporins Cephalosporins are a group of bactericidal beta-lactam antibiotics (similar to penicillins) that exert their effects by preventing bacteria from producing their cell walls, ultimately leading to cell death. Cephalosporins are categorized by generation and all drug names begin with “cef-” or “ceph-.” Cephalosporins
• MRSA MRSA A strain of Staphylococcus aureus that is non-susceptible to the action of methicillin. The mechanism of resistance usually involves modification of normal or the presence of acquired penicillin binding proteins. Staphylococcus: vancomycin Vancomycin Antibacterial obtained from streptomyces orientalis. It is a glycopeptide related to ristocetin that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear. Glycopeptides
• Vibrio vulnificus Vibrio vulnificus A species of halophilic bacteria in the genus vibrio, which lives in warm seawater. It can cause infections in those who eat raw contaminated seafood or have open wounds exposed to seawater. Vibrio → treat with both:
  • Tetracyclines Tetracyclines Tetracyclines are a class of broad-spectrum antibiotics indicated for a wide variety of bacterial infections. These medications bind the 30S ribosomal subunit to inhibit protein synthesis of bacteria. Tetracyclines cover gram-positive and gram-negative organisms, as well as atypical bacteria such as chlamydia, mycoplasma, spirochetes, and even protozoa. Tetracyclines (e.g., doxycycline, minocycline Minocycline A tetracycline analog, having a 7-dimethylamino and lacking the 5 methyl and hydroxyl groups, which is effective against tetracycline-resistant staphylococcus infections. Tetracyclines) 
  • 3rd-generation cephalosporin Cephalosporin Multidrug-resistant Organisms and Nosocomial Infections (e.g., ceftriaxone Ceftriaxone A broad-spectrum cephalosporin antibiotic and cefotaxime derivative with a very long half-life and high penetrability to meninges, eyes and inner ears. Cephalosporins or cefotaxime Cefotaxime Semisynthetic broad-spectrum cephalosporin. Cephalosporins)
• Clostridium spp.: penicillin Penicillin Rheumatic Fever + clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides

Duration of antibiotic therapy:^[6–9]

• Duration recommendations are variable Variable Variables represent information about something that can change. The design of the measurement scales, or of the methods for obtaining information, will determine the data gathered and the characteristics of that data. As a result, a variable can be qualitative or quantitative, and may be further classified into subgroups. Types of Variables.
• Consider continuing antibiotics until:
  • No further surgical debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome is needed
  • There is clinical improvement
  • There no fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever for 48–72 hours

Postoperative care Postoperative care After any procedure performed in the operating room, all patients must undergo close observation at least in the recovery room. After larger procedures and for patients who require hospitalization, observation must continue on the surgical ward. The primary intent of this practice is the early detection of postoperative complications. Postoperative Care^[6–9]

The majority of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will require monitoring in an intensive care unit for close monitoring and management.

• Hemodynamic support:
  • Aggressive resuscitation Resuscitation The restoration to life or consciousness of one apparently dead. . Neonatal Respiratory Distress Syndrome with intravenous crystalloid Crystalloid Isotonic solutions of mineral salts, such as ringer’s lactate and sodium chloride (saline solution), used in fluid therapy to rehydrate blood volume. Intravenous Fluids fluids
  • Vasopressor Vasopressor Acute Cholangitis support for septic shock Septic shock Sepsis associated with hypotension or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to lactic acidosis; oliguria; or acute alteration in mental status. Sepsis and Septic Shock with MAP target ≥65 mm Hg ( norepinephrine Norepinephrine Precursor of epinephrine that is secreted by the adrenal medulla and is a widespread central and autonomic neurotransmitter. Norepinephrine is the principal transmitter of most postganglionic sympathetic fibers, and of the diffuse projection system in the brain that arises from the locus ceruleus. Receptors and Neurotransmitters of the CNS is first line)
• Monitor hemoglobin and transfuse for blood loss associated with repeated debridements.
• Analgesia Analgesia Methods of pain relief that may be used with or in place of analgesics. Anesthesiology: History and Basic Concepts
• Nutritional support
• Wound care consult:
  •  Leave wounds open after debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome.
  • Once sthe wound is stable (not requiring repeated debridements), may use negative-pressure wound therapy (NPWT/wound vac). 
  • Use wound vac cautiously in anaerobic infection.

Controversial therapies^[6–9]

The following may be considered due to a potential benefit, but there are not much clinical data:

• IVIG IVIG Dermatomyositis (to neutralize toxin)
• Hyperbaric oxygen Hyperbaric oxygen The therapeutic intermittent administration of oxygen in a chamber at greater than sea-level atmospheric pressures (three atmospheres). It is considered effective treatment for air and gas embolisms, smoke inhalation, acute carbon monoxide poisoning, caisson disease, clostridial gangrene, etc. The list of treatment modalities includes stroke. Decompression Sickness therapy (used as an adjuvant Adjuvant Substances that augment, stimulate, activate, potentiate, or modulate the immune response at either the cellular or humoral level. The classical agents (freund’s adjuvant, bcg, corynebacterium parvum, et al.) contain bacterial antigens. Some are endogenous (e.g., histamine, interferon, transfer factor, tuftsin, interleukin-1). Their mode of action is either non-specific, resulting in increased immune responsiveness to a wide variety of antigens, or antigen-specific, i.e., affecting a restricted type of immune response to a narrow group of antigens. The therapeutic efficacy of many biological response modifiers is related to their antigen-specific immunoadjuvanticity. Vaccination for source control Source Control Surgical Infections): not consistently recommended
• AB103 (inflammatory modulator): remains experimental

Complications^[1,2]

• Septic shock Septic shock Sepsis associated with hypotension or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to lactic acidosis; oliguria; or acute alteration in mental status. Sepsis and Septic Shock
• Toxic shock syndrome Toxic Shock Syndrome Toxic shock syndrome (TSS) is an acute, multi-systemic disease caused by the toxin-producing bacteria, Staphylococcus aureus and Streptococcus pyogenes. Staphylococcal TSS is more common and associated with tampons and nasal packing. Toxic Shock Syndrome: NF NF Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis caused by GAS strains with M proteins Proteins Linear polypeptides that are synthesized on ribosomes and may be further modified, crosslinked, cleaved, or assembled into complex proteins with several subunits. The specific sequence of amino acids determines the shape the polypeptide will take, during protein folding, and the function of the protein. Energy Homeostasis types 1 and 3 is associated with streptococcal toxic shock syndrome Streptococcal Toxic Shock Syndrome Toxic Shock Syndrome in ~ 50% of cases,
• Multisystem organ failure
• Limb loss and severe scarring Scarring Inflammation
• Death

Differential Diagnosis

• Cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis: a common bacterial skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions infection that affects the deeper layers of the dermis Dermis A layer of vascularized connective tissue underneath the epidermis. The surface of the dermis contains innervated papillae. Embedded in or beneath the dermis are sweat glands; hair follicles; and sebaceous glands. Skin: Structure and Functions and subcutaneous tissue Subcutaneous tissue Loose connective tissue lying under the dermis, which binds skin loosely to subjacent tissues. It may contain a pad of adipocytes, which vary in number according to the area of the body and vary in size according to the nutritional state. Soft Tissue Abscess. This condition is most commonly caused by S. aureus S. aureus Potentially pathogenic bacteria found in nasal membranes, skin, hair follicles, and perineum of warm-blooded animals. They may cause a wide range of infections and intoxications. Staphylococcus and S. pyogenes. Cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis presents as an erythematous, edematous area that is warm and tender to the touch. Crepitus Crepitus Osteoarthritis, necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage, and systemic toxicity Toxicity Dosage Calculation are not usually present. Diagnosis is clinical, and management involves antibiotics tailored to the suspected organism.
• Pyoderma gangrenosum Pyoderma gangrenosum An idiopathic, rapidly evolving, and severely debilitating disease occurring most commonly in association with chronic ulcerative colitis. It is characterized by the presence of boggy, purplish ulcers with undermined borders, appearing mostly on the legs. The majority of cases are in people between 40 and 60 years old. Its etiology is unknown. Crohn Disease: neutrophilic dermatosis Neutrophilic Dermatosis Rheumatoid Arthritis that presents with inflammation Inflammation Inflammation is a complex set of responses to infection and injury involving leukocytes as the principal cellular mediators in the body’s defense against pathogenic organisms. Inflammation is also seen as a response to tissue injury in the process of wound healing. The 5 cardinal signs of inflammation are pain, heat, redness, swelling, and loss of function. Inflammation and ulceration Ulceration Corneal Abrasions, Erosion, and Ulcers of the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with a painful, inflamed papule Papule Elevated lesion < 1 cm in diameter Generalized and Localized Rashes that progresses to an ulcer with irregular borders and purulent drainage. Unlike necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis, there is rarely systemic toxicity Toxicity Dosage Calculation, the involvement of the fascial planes, or improvement with antibiotics. This condition will worsen with debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome. Pyoderma gangrenosum Pyoderma gangrenosum An idiopathic, rapidly evolving, and severely debilitating disease occurring most commonly in association with chronic ulcerative colitis. It is characterized by the presence of boggy, purplish ulcers with undermined borders, appearing mostly on the legs. The majority of cases are in people between 40 and 60 years old. Its etiology is unknown. Crohn Disease is based on the clinical assessment and histologic findings. This is managed with immunosuppressive therapy.
• Pyomyositis: infection of the skeletal muscle that results from hematogenous Hematogenous Hepatocellular Carcinoma (HCC) and Liver Metastases spread from a primary infected source. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with localized pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, fevers, and a variable Variable Variables represent information about something that can change. The design of the measurement scales, or of the methods for obtaining information, will determine the data gathered and the characteristics of that data. As a result, a variable can be qualitative or quantitative, and may be further classified into subgroups. Types of Variables degree of skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions findings from minimal erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion to severe tenderness, induration Induration Dermatologic Examination, and edema Edema Edema is a condition in which excess serous fluid accumulates in the body cavity or interstitial space of connective tissues. Edema is a symptom observed in several medical conditions. It can be categorized into 2 types, namely, peripheral (in the extremities) and internal (in an organ or body cavity). Edema. The diagnosis is made with imaging and culture data. Management typically consists of percutaneous drainage Percutaneous Drainage Echinococcus/Echinococcosis or, in severe cases, open surgical drainage with antibiotic therapy.
• Gas gangrene Gangrene Death and putrefaction of tissue usually due to a loss of blood supply. Small Bowel Obstruction ( clostridial myonecrosis Clostridial myonecrosis Gas gangrene, also known as clostridial myonecrosis, is a life-threatening muscle and soft tissue infection that usually develops after traumatic inoculation with clostridium perfringens (C. perfringens), but can also develop spontaneously in association with other Clostridium species. Gas Gangrene): traumatic or spontaneous ( C. perfringens C. perfringens The most common etiologic agent of gas gangrene. It is differentiable into several distinct types based on the distribution of twelve different toxins. Gas Gangrene,  C. septicum C. septicum A species of gram-positive bacteria in the family clostridiaceae. Infections have a strong association with malignancies and also with gas gangrene. Gas Gangrene), with prominent tissue gas on imaging and crepitus Crepitus Osteoarthritis, difficult to distinguish from type I NF NF Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis. Infection of the muscle presenting with increasing pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways within 24 hours of injury. Imaging shows gas in tissue (also seen in type I NSTI); tissue Gram stain Gram stain Klebsiella shows large gram-positive Gram-Positive Penicillins/gram-variable rods, and surgery reveals non-contracting, non-bleeding muscle. Management includes urgent debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome and  penicillin Penicillin Rheumatic Fever plus clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides for 10–14 days.
• Acute compartment syndrome Compartment Syndrome Compartment syndrome is a surgical emergency usually occurring secondary to trauma. The condition is marked by increased pressure within a compartment that compromises the circulation and function of the tissues within that space. Compartment Syndrome: increased pressure in the fascial compartment (form trauma, rebleeding, etc ETC The electron transport chain (ETC) sends electrons through a series of proteins, which generate an electrochemical proton gradient that produces energy in the form of adenosine triphosphate (ATP). Electron Transport Chain (ETC)). Condition can coexist with or mimic deep NSTI ( pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways out of proportion, with tense/swollen extremity, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways on passive stretch); requires compartment pressure measurement for diagnosis and treatment is emergent fasciotomy Fasciotomy Surgical incision on the fascia. It is used to decompress compartment pressure (e.g. in compartment syndromes; circumferential burns and extremity injuries) or to release contractures (e.g. in dupuytren’s contracture). Compartment Syndrome.

Billing and Coding

Diagnosis Codes:

This code is used to diagnose necrotizing fasciitis, a rare but life-threatening, rapidly progressing bacterial infection of the soft tissue and fascia (“flesh-eating disease”).

Procedures/Interventions:

This CPT code is for emergent, aggressive surgical debridement Debridement The removal of foreign material and devitalized or contaminated tissue from or adjacent to a traumatic or infected lesion until surrounding healthy tissue is exposed. Stevens-Johnson Syndrome, which is the most critical component of treatment. All necrotic tissue must be removed to control the infection, often requiring multiple operations.

Medications:

These codes are for the empiric, broad-spectrum Broad-Spectrum Fluoroquinolones intravenous antibiotics (e.g., piperacillin Piperacillin Semisynthetic, broad-spectrum, ampicillin derived ureidopenicillin antibiotic proposed for pseudomonas infections. It is also used in combination with other antibiotics. Penicillins/ tazobactam Tazobactam A penicillanic acid and sulfone derivative and potent beta-lactamase inhibitor that enhances the activity of other anti-bacterial agents against beta-lactamase producing bacteria. Cephalosporins, vancomycin Vancomycin Antibacterial obtained from streptomyces orientalis. It is a glycopeptide related to ristocetin that inhibits bacterial cell wall assembly and is toxic to kidneys and the inner ear. Glycopeptides, clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides) that are started immediately to cover the polymicrobial nature of the infection.

Complications:

This code is for septic shock Septic shock Sepsis associated with hypotension or hypoperfusion despite adequate fluid resuscitation. Perfusion abnormalities may include, but are not limited to lactic acidosis; oliguria; or acute alteration in mental status. Sepsis and Septic Shock, a common and often fatal complication of necrotizing fasciitis Necrotizing fasciitis Necrotizing fasciitis is a life-threatening infection that causes rapid destruction and necrosis of the fascia and subcutaneous tissues. Patients may present with significant pain out of proportion to the presenting symptoms and rapidly progressive erythema of the affected area. Necrotizing Fasciitis, resulting from the overwhelming systemic inflammatory response to the infection.