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Spider Bites

Spider bites are a rare cause of morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status and mortality Mortality All deaths reported in a given population. Measures of Health Status. Almost all spiders are venomous, but the majority do not have the ability to penetrate 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 for envenomation. Brown recluse and black widow spiders are the most common causes of serious systemic reactions in the United States. The brown recluse spider contains a necrotizing venom that can lead to a painful, blistering, necrotic wound, which can be complicated by fevers, myalgias Myalgias Painful sensation in the muscles. Tick-borne Encephalitis Virus, hemolysis, seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures, and 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. Black widow spiders have a neurotoxic venom that can cause muscle cramping and rigidity Rigidity Continuous involuntary sustained muscle contraction which is often a manifestation of basal ganglia diseases. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity. Megacolon (often manifesting as severe abdominal pain Abdominal Pain Acute Abdomen), vital sign instability, lacrimation and salivation, ptosis Ptosis Cranial Nerve Palsies, and respiratory distress. The diagnosis is clinical. Management includes wound care, pain management Pain Management Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Pain is a subjective experience. Acute pain lasts < 3 months and typically has a specific, identifiable cause. Pain Management, supportive care for systemic symptoms, antivenom for black widow bites, and delayed 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 of necrotic tissue in brown recluse bites.

Last updated: 10 Mar, 2022

Editorial responsibility: Stanley Oiseth, Lindsay Jones, Evelin Maza

Epidemiology and Species

Epidemiology

  • Spider bites are rarely a cause of serious morbidity Morbidity The proportion of patients with a particular disease during a given year per given unit of population. Measures of Health Status or mortality Mortality All deaths reported in a given population. Measures of Health Status.
  • < 3 deaths per year in the United States
  • Severe symptoms and death are more likely to occur in children.

Clinically relevant species

In the United States, the following spider bites can result in serious systemic symptoms: 

Brown recluse spider:

  • Found in central and southern United States
  • Occupy dry, secluded areas including: 
    • Basements
    • Attics
    • Wood piles
    • Other dark, undisturbed areas
Brown recluse spider

The highly venomous brown recluse spider Loxosceles reclusa:
Note the characteristic violin-shaped marking visible on its dorsal cephalothorax.

Image: “1125” by Margaret Parsons. License: Public Domain

Black widow spider:

  • Found worldwide, including the southern and western United States
  • Prefers outdoor habitats (rarely found indoors):
    • Firewood piles
    • Garages
    • Gardening equipment
    • Trash
    • Outdoor furniture
Female black widow spider

A female black widow spider, Latrodectus mactans, in the process of spinning her web upon a tree branch:
Note the characteristic red hourglass located on her inferior abdominal surface, which can vary in coloration from yellowish to shades of orange and red. The female’s body is a shiny, jet-black color.

Image: “20260” by James Gathany. License: Public Domain

Pathophysiology

Brown recluse spider

  • Necrotizing venom
  • Cytotoxic Cytotoxic Parvovirus B19 and hemolytic
  • Components:
    • Sphingomyelinase D or phospholipase D Phospholipase D An enzyme found mostly in plant tissue. It hydrolyzes glycerophosphatides with the formation of a phosphatidic acid and a nitrogenous base such as choline. This enzyme also catalyzes transphosphatidylation reactions. Yersinia pestis/Plague
      • Complement-mediated erythrocyte destruction (hemolysis)
      • Tissue destruction/ necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage
      • 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
    • Insecticidal toxins
    • Proteases Proteases Proteins and Peptides → degradation of:
      • Collagen Collagen A polypeptide substance comprising about one third of the total protein in mammalian organisms. It is the main constituent of skin; connective tissue; and the organic substance of bones (bone and bones) and teeth (tooth). Connective Tissue: Histology
      • Fibronectin Fibronectin Glycoproteins found on the surfaces of cells, particularly in fibrillar structures. The proteins are lost or reduced when these cells undergo viral or chemical transformation. They are highly susceptible to proteolysis and are substrates for activated blood coagulation factor VIII. The forms present in plasma are called cold-insoluble globulins. Connective Tissue: Histology
      • Fibrinogen Fibrinogen Plasma glycoprotein clotted by thrombin, composed of a dimer of three non-identical pairs of polypeptide chains (alpha, beta, gamma) held together by disulfide bonds. Fibrinogen clotting is a sol-gel change involving complex molecular arrangements: whereas fibrinogen is cleaved by thrombin to form polypeptides a and b, the proteolytic action of other enzymes yields different fibrinogen degradation products. Hemostasis
      • Elastin

Black widow spider

  • Neurotoxic venom
  • Affects neuromuscular transmission and autonomic function
  • Alpha-latrotoxin is the primary toxin:
    • Binds irreversibly to receptors Receptors Receptors are proteins located either on the surface of or within a cell that can bind to signaling molecules known as ligands (e.g., hormones) and cause some type of response within the cell. Receptors on presynaptic neurons Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system. Nervous System: Histology
    • Causes an influx of calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes ions
    • Results in the release Release Release of a virus from the host cell following virus assembly and maturation. Egress can occur by host cell lysis, exocytosis, or budding through the plasma membrane. Virology of:
      • Acetylcholine Acetylcholine A neurotransmitter found at neuromuscular junctions, autonomic ganglia, parasympathetic effector junctions, a subset of sympathetic effector junctions, and at many sites in the central nervous system. Receptors and Neurotransmitters of the CNS
      • Dopamine Dopamine One of the catecholamine neurotransmitters in the brain. It is derived from tyrosine and is the precursor to norepinephrine and epinephrine. Dopamine is a major transmitter in the extrapyramidal system of the brain, and important in regulating movement. Receptors and Neurotransmitters of the CNS
      • 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
      • Epinephrine Epinephrine The active sympathomimetic hormone from the adrenal medulla. It stimulates both the alpha- and beta- adrenergic systems, causes systemic vasoconstriction and gastrointestinal relaxation, stimulates the heart, and dilates bronchi and cerebral vessels. Sympathomimetic Drugs
      • Glutamate Glutamate Derivatives of glutamic acid. Included under this heading are a broad variety of acid forms, salts, esters, and amides that contain the 2-aminopentanedioic acid structure. Synthesis of Nonessential Amino Acids

Clinical Presentation

Brown recluse spider

  • Loxoscelism: local and systemic manifestations of a recluse spider bite
  • Bite site:
  • Localized symptoms:
    • May be painless initially
    • Severe pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways of the entire extremity develops 30‒60 minutes later.
    • Pruritis
  • Systemic symptoms:
    • 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 and chills Chills The sudden sensation of being cold. It may be accompanied by shivering. Fever
    • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics and vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
    • Arthralgias and myalgias Myalgias Painful sensation in the muscles. Tick-borne Encephalitis Virus
    • Generalized, morbilliform Morbilliform Erythema Infectiosum rash Rash Rocky Mountain Spotted Fever
    • Jaundice Jaundice Jaundice is the abnormal yellowing of the skin and/or sclera caused by the accumulation of bilirubin. Hyperbilirubinemia is caused by either an increase in bilirubin production or a decrease in the hepatic uptake, conjugation, or excretion of bilirubin. Jaundice and dark urine Urine Liquid by-product of excretion produced in the kidneys, temporarily stored in the bladder until discharge through the urethra. Bowen Disease and Erythroplasia of Queyrat (from hemolysis)
  • Complications:
    • Seizure
    • 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
    • Disseminated intravascular coagulation Disseminated intravascular coagulation Disseminated intravascular coagulation (DIC) is a condition characterized by systemic bodywide activation of the coagulation cascade. This cascade results in both widespread microvascular thrombi contributing to multiple organ dysfunction and consumption of clotting factors and platelets, leading to hemorrhage. Disseminated Intravascular Coagulation
    • Thrombocytopenia Thrombocytopenia Thrombocytopenia occurs when the platelet count is < 150,000 per microliter. The normal range for platelets is usually 150,000-450,000/µL of whole blood. Thrombocytopenia can be a result of decreased production, increased destruction, or splenic sequestration of platelets. Patients are often asymptomatic until platelet counts are < 50,000/µL. Thrombocytopenia
    • Hemolysis
    • Rhabdomyolysis Rhabdomyolysis Rhabdomyolysis is characterized by muscle necrosis and the release of toxic intracellular contents, especially myoglobin, into the circulation. Rhabdomyolysis
    • 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

Black widow spider

  • Latrodectism: local and systemic manifestations of a black widow spider bite
  • Bite site:
    • 2 small puncture wounds may be seen.
    • Erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion 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 around the bite
    • Central, pale clearing develops (target appearance).
  • Local symptoms:
    • Immediate, sharp, stinging pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
    • Piloerection
    • Isolated diaphoresis
  • Systemic symptoms:
    • Vital signs (with venom effects):
      • Hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension
      • 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
      • Tachypnea Tachypnea Increased respiratory rate. Pulmonary Examination
      • Hyperthermia
    • Severe cramping pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and rigidity Rigidity Continuous involuntary sustained muscle contraction which is often a manifestation of basal ganglia diseases. When an affected muscle is passively stretched, the degree of resistance remains constant regardless of the rate at which the muscle is stretched. This feature helps to distinguish rigidity from muscle spasticity. Megacolon of large muscle groups:
      • Abdomen (mimicking a surgical abdomen)
      • Back
      • Chest
      • Thighs
    • Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess
    • Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics and vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia
    • Salivation and lacrimation
    • Anxiety Anxiety Feelings or emotions of dread, apprehension, and impending disaster but not disabling as with anxiety disorders. Generalized Anxiety Disorder
    • Ptosis Ptosis Cranial Nerve Palsies
    • Facial and extremity swelling Swelling Inflammation
  • Complications:
    • Respiratory distress
    • Hypertensive emergency Hypertensive emergency A condition of markedly elevated blood pressure with diastolic pressure usually greater than 120 mm hg. Malignant hypertension is characterized by widespread vascular damage, papilledema, retinopathy, hypertensive encephalopathy, and renal dysfunction. Uncontrolled Hypertension
    • Rhabdomyolysis Rhabdomyolysis Rhabdomyolysis is characterized by muscle necrosis and the release of toxic intracellular contents, especially myoglobin, into the circulation. Rhabdomyolysis
    • Myocarditis Myocarditis Myocarditis is an inflammatory disease of the myocardium, which may occur alone or in association with a systemic process. There are numerous etiologies of myocarditis, but all lead to inflammation and myocyte injury, most often leading to signs and symptoms of heart failure. Myocarditis
    • Ileus Ileus A condition caused by the lack of intestinal peristalsis or intestinal motility without any mechanical obstruction. This interference of the flow of intestinal contents often leads to intestinal obstruction. Ileus may be classified into postoperative, inflammatory, metabolic, neurogenic, and drug-induced. Small Bowel Obstruction

Diagnosis

Diagnosis

Spider bites are a clinical diagnosis.

  • Spider bites are often falsely suspected by patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship, especially in nonendemic regions.
  • Witnessing the bite and proper identification Identification Defense Mechanisms of the spider are required for confirmation.
  • 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 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 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 and other conditions (e.g., vasculitis Vasculitis Inflammation of any one of the blood vessels, including the arteries; veins; and rest of the vasculature system in the body. Systemic Lupus Erythematosus) should be excluded if the above conditions are not fulfilled.

Mnemonic

NOT RECLUSE” can help exclude the diagnosis of a brown recluse spider bite:

  • N: Numerous lesions are not typical of a spider bite.
  • O: occurrence (bites tend to occur when disturbing a spider)
  • T: timing (most bites occur between April and October)
  • R: red center (recluse bites have a pale center)
  • E: Elevated lesions are not typical with recluse spider bites.
  • C: Chronic lesions are rare in spider bites.
  • L: Large lesions are rare (most bite lesions are 2 cm or smaller).
  • U: ulcerates too early (if < 1 week, consider other conditions)
  • S: Swollen bite lesions usually occur only on the feet or face.
  • E: Exudative lesions do not occur.

Management

General measures

  • Wound cleansing
  • Elevation of the extremity
  • Ensure tetanus Tetanus Tetanus is a bacterial infection caused by Clostridium tetani, a gram-positive obligate anaerobic bacterium commonly found in soil that enters the body through a contaminated wound. C. tetani produces a neurotoxin that blocks the release of inhibitory neurotransmitters and causes prolonged tonic muscle contractions. Tetanus immunization is up to date.
  • Hospitalization Hospitalization The confinement of a patient in a hospital. Delirium and management for systemic manifestations

Additional measures for brown recluse spider bites

  • Cold compresses:
    • Sphingomyelinase D is temperature dependent.
    • Slows the necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage process
  • Pain management Pain Management Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Pain is a subjective experience. Acute pain lasts < 3 months and typically has a specific, identifiable cause. Pain Management:
    • NSAIDs NSAIDS Primary vs Secondary Headaches
    • Opioids Opioids Opiates are drugs that are derived from the sap of the opium poppy. Opiates have been used since antiquity for the relief of acute severe pain. Opioids are synthetic opiates with properties that are substantially similar to those of opiates. Opioid Analgesics
  • Surgical excision of necrotic regions should be delayed until fully demarcated.

Additional measures for black widow spider bites

  • Pain management Pain Management Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. Pain is a subjective experience. Acute pain lasts < 3 months and typically has a specific, identifiable cause. Pain Management:
    • Opioids Opioids Opiates are drugs that are derived from the sap of the opium poppy. Opiates have been used since antiquity for the relief of acute severe pain. Opioids are synthetic opiates with properties that are substantially similar to those of opiates. Opioid Analgesics
    • Benzodiazepines Benzodiazepines Benzodiazepines work on the gamma-aminobutyric acid type A (GABAA) receptor to produce inhibitory effects on the CNS. Benzodiazepines do not mimic GABA, the main inhibitory neurotransmitter in humans, but instead potentiate GABA activity. Benzodiazepines for muscle relaxation
  • Black widow spider antivenom

Differential Diagnosis

  • Insect sting: bee, wasp, and ant stings can cause envenomation with localized swelling Swelling Inflammation. Some patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will develop a severe allergic reaction, including anaphylaxis Anaphylaxis An acute hypersensitivity reaction due to exposure to a previously encountered antigen. The reaction may include rapidly progressing urticaria, respiratory distress, vascular collapse, systemic shock, and death. Type I Hypersensitivity Reaction. Neurologic manifestations and tissue necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage are not usually present. The diagnosis is clinical. Management includes removing the stinger (if present), antihistamines Antihistamines Antihistamines are drugs that target histamine receptors, particularly H1 and H2 receptors. H1 antagonists are competitive and reversible inhibitors of H1 receptors. First-generation antihistamines cross the blood-brain barrier and can cause sedation. Antihistamines, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways control, and emergency care for anaphylaxis Anaphylaxis An acute hypersensitivity reaction due to exposure to a previously encountered antigen. The reaction may include rapidly progressing urticaria, respiratory distress, vascular collapse, systemic shock, and death. Type I Hypersensitivity Reaction.
  • Scorpion sting: most scorpion stings Scorpion stings Insect and scorpion stings are a rare cause of mortality. Hymenoptera insects and Centruroides scorpions can potentially lead to serious symptoms due to envenomation. Pain, swelling, erythema, and warmth are common at the site of a sting. Insect and Scorpion Stings are harmless; however, the bark scorpion is venomous. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will have pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and swelling Swelling Inflammation at the site of the sting. Systemic manifestations can include muscle spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy, diaphoresis, abnormal neck Neck The part of a human or animal body connecting the head to the rest of the body. Peritonsillar Abscess and head movements, 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, hypertension Hypertension Hypertension, or high blood pressure, is a common disease that manifests as elevated systemic arterial pressures. Hypertension is most often asymptomatic and is found incidentally as part of a routine physical examination or during triage for an unrelated medical encounter. Hypertension, and respiratory distress. The diagnosis is clinical. Management includes supportive care, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways control, benzodiazepines Benzodiazepines Benzodiazepines work on the gamma-aminobutyric acid type A (GABAA) receptor to produce inhibitory effects on the CNS. Benzodiazepines do not mimic GABA, the main inhibitory neurotransmitter in humans, but instead potentiate GABA activity. Benzodiazepines for muscle spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy, and antivenom.
  • 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 Staphylococcus Staphylococcus Staphylococcus is a medically important genera of Gram-positive, aerobic cocci. These bacteria form clusters resembling grapes on culture plates. Staphylococci are ubiquitous for humans, and many strains compose the normal skin flora. Staphylococcus aureus and 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. 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. Bullae Bullae Erythema Multiforme, 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. The diagnosis is clinical, and management involves antibiotics tailored to the suspected organism.
  • 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: a life-threatening infection that causes rapid destruction 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 of the 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 and subcutaneous tissues. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may have significant pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and rapidly progressive erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion of the affected area. 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, 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 mental status Altered Mental Status Sepsis in Children, and multisystem organ failure may also be present. The diagnosis is primarily clinical. This type of infection is a surgical emergency Surgical Emergency Acute Abdomen and requires 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, parenteral antibiotics, and close hemodynamic monitoring.
  • Anthrax Anthrax Anthrax is an infection caused by the bacterium Bacillus anthracis, which usually targets the skin, lungs, or intestines. Anthrax is a zoonotic disease and is usually transmitted to humans from animals or through animal products. Symptoms depend on which organ system is affected. Anthrax: an infection caused by Bacillus Bacillus Bacillus are aerobic, spore-forming, gram-positive bacilli. Two pathogenic species are Bacillus anthracis (B. anthracis) and B. cereus. Bacillus anthracis. Cutaneous infection presents with a painless, pruritic papule Papule Elevated lesion < 1 cm in diameter Generalized and Localized Rashes that enlarges to form an ulcer with a black eschar. Systemic symptoms such as 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, lymphadenopathy Lymphadenopathy Lymphadenopathy is lymph node enlargement (> 1 cm) and is benign and self-limited in most patients. Etiologies include malignancy, infection, and autoimmune disorders, as well as iatrogenic causes such as the use of certain medications. Generalized lymphadenopathy often indicates underlying systemic disease. Lymphadenopathy, myalgia Myalgia Painful sensation in the muscles. Ion Channel Myopathy, and nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics are common. Hematologic, neurologic, and renal complications are not seen. The diagnosis requires identification Identification Defense Mechanisms of the organism on culture, direct fluorescent antibody Direct Fluorescent Antibody A form of fluorescent antibody technique utilizing a fluorochrome conjugated to an antibody, which is added directly to a tissue or cell suspension for the detection of a specific antigen. Congenital TORCH Infections testing, or PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR). Antibiotics are used for treatment.
  • Mesenteric ischemia Mesenteric Ischemia Mesenteric ischemia is a rare, life-threatening condition caused by inadequate blood flow through the mesenteric vessels, which results in ischemia and necrosis of the intestinal wall. Mesenteric ischemia can be either acute or chronic. Mesenteric Ischemia: interruption in blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure through the mesenteric arteries Arteries Arteries are tubular collections of cells that transport oxygenated blood and nutrients from the heart to the tissues of the body. The blood passes through the arteries in order of decreasing luminal diameter, starting in the largest artery (the aorta) and ending in the small arterioles. Arteries are classified into 3 types: large elastic arteries, medium muscular arteries, and small arteries and arterioles. Arteries: Histology resulting in 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 of the bowel. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with abdominal pain Abdominal Pain Acute Abdomen out of proportion to the clinical exam. 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, hematochezia Hematochezia Gastrointestinal Bleeding, and 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 occur with bowel infarction. No 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 lesion will be seen. Computed tomography with angiography Angiography Radiography of blood vessels after injection of a contrast medium. Cardiac Surgery is the diagnostic modality of choice. Management is often surgical and focuses on re-establishing blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure to the intestines.
  • Hypocalcemia Hypocalcemia Hypocalcemia, a serum calcium < 8.5 mg/dL, can result from various conditions. The causes may include hypoparathyroidism, drugs, disorders leading to vitamin D deficiency, and more. Calcium levels are regulated and affected by different elements such as dietary intake, parathyroid hormone (PTH), vitamin D, pH, and albumin. Presentation can range from an asymptomatic (mild deficiency) to a life-threatening condition (acute, significant deficiency). Hypocalcemia: a low plasma Plasma The residual portion of blood that is left after removal of blood cells by centrifugation without prior blood coagulation. Transfusion Products calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes concentration that may be due to hypoparathyroidism Hypoparathyroidism Hypoparathyroidism is defined as reduced parathyroid hormone (PTH) levels due to poor function of the parathyroid glands. The cause of hypoparathyroidism is most commonly iatrogenic following neck surgery, but it can also be associated with genetic or autoimmune disorders as well as infiltrative diseases causing destruction of the normal parathyroid tissue. Hypoparathyroidism, vitamin D deficiency Vitamin D Deficiency A nutritional condition produced by a deficiency of vitamin D in the diet, insufficient production of vitamin D in the skin, inadequate absorption of vitamin D from the diet, or abnormal conversion of vitamin D to its bioactive metabolites. It is manifested clinically as rickets in children and osteomalacia in adults. Fat-soluble Vitamins and their Deficiencies, or renal disease. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with severe hypocalcemia Hypocalcemia Hypocalcemia, a serum calcium < 8.5 mg/dL, can result from various conditions. The causes may include hypoparathyroidism, drugs, disorders leading to vitamin D deficiency, and more. Calcium levels are regulated and affected by different elements such as dietary intake, parathyroid hormone (PTH), vitamin D, pH, and albumin. Presentation can range from an asymptomatic (mild deficiency) to a life-threatening condition (acute, significant deficiency). Hypocalcemia may present with paresthesias Paresthesias Subjective cutaneous sensations (e.g., cold, warmth, tingling, pressure, etc.) that are experienced spontaneously in the absence of stimulation. Posterior Cord Syndrome, muscle cramping, tetany Tetany A disorder characterized by muscle twitches, cramps, and carpopedal spasm, and when severe, laryngospasm and seizures. This condition is associated with unstable depolarization of axonal membranes, primarily in the peripheral nervous system. Tetany usually results from hypocalcemia or reduced serum levels of magnesium that may be associated with hyperventilation; hypoparathyroidism; rickets; uremia; or other conditions. Hypocalcemia, hyperreflexia, and seizures Seizures A seizure is abnormal electrical activity of the neurons in the cerebral cortex that can manifest in numerous ways depending on the region of the brain affected. Seizures consist of a sudden imbalance that occurs between the excitatory and inhibitory signals in cortical neurons, creating a net excitation. The 2 major classes of seizures are focal and generalized. Seizures. 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 lesion and other systemic symptoms of a black widow spider bite will not be seen. Low serum calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes levels provide the diagnosis, and management requires calcium Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Electrolytes supplementation and correction of the underlying etiology.

References

  1. Centers for Disease Control and Prevention. Venomous spiders. National Institute for Occupational Safety and Health (NIOSH). Reviewed May 31, 2018. https://www.cdc.gov/niosh/topics/spiders/
  2. Bush, S.P., Cohen, J.P., Green, S. (2020). Widow spider envenomation. In Alcock, J. (Ed.). Medscape. Retrieved March 24, 2021, from https://emedicine.medscape.com/article/772196-overview
  3. Arnold, T.C. (2018). Brown recluse spider envenomation. In Alcock, J. (Ed.). Medscape. Retrieved March 24, 2021, from https://emedicine.medscape.com/article/772295-overview
  4. Anoka, I.A., Robb, E.L., Baker, M.B. (2020). Brown recluse spider toxicity. StatPearls. Retrieved March 24, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK537045/
  5. Williams, M., Anderson, J., Nappe, T. (2020). Black widow spider toxicity. StatPearls. Retrieved March 24, 2021, from https://www.statpearls.com/ArticleLibrary/viewarticle/29298
  6. Barish, R.A., Arnold, T. (2020). Spider bites. MSD Manual Professional Version. Retrieved March 24, 2021, from https://www.msdmanuals.com/professional/injuries-poisoning/bites-and-stings/spider-bites

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