Orbital and Preseptal Cellulitis

Overview

Orbital anatomy

Orbit Orbit The orbit is the cavity of the skull in which the eye and its appendages are situated. The orbit is composed of 7 bones and has a pyramidal shape, with its apex pointed posteromedially. The orbital contents comprise the eye, extraocular muscles, 5 cranial nerves, blood vessels, fat, the lacrimal apparatus, among others. Orbit and Extraocular Muscles: Anatomy:

• Cavity of the skull Skull The skull (cranium) is the skeletal structure of the head supporting the face and forming a protective cavity for the brain. The skull consists of 22 bones divided into the viscerocranium (facial skeleton) and the neurocranium. Skull: Anatomy in which the eye and its appendages are situated
• Contents are made up of the eye, 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, extraocular muscles, cranial nerves Cranial nerves There are 12 pairs of cranial nerves (CNs), which run from the brain to various parts of the head, neck, and trunk. The CNs can be sensory or motor or both. The CNs are named and numbered in Roman numerals according to their location, from the front to the back of the brain. The 12 Cranial Nerves: Overview and Functions, blood vessels, fat, and lacrimal and eyelid structures.
• Flanked by paranasal sinuses Paranasal Sinuses The 4 pair of paranasal sinuses include the maxillary, ethmoid, sphenoid, and frontal sinuses. The sinuses are a group of air-filled cavities located within the facial and cranial skeleton; all are connected to the main nasal cavity and nasopharynx. Paranasal Sinuses: Anatomy:
  • Frontal sinus Frontal sinus One of the paired, but seldom symmetrical, air spaces located between the inner and outer compact layers of the frontal bone in the forehead. Paranasal Sinuses: Anatomy (superior to the orbit Orbit The orbit is the cavity of the skull in which the eye and its appendages are situated. The orbit is composed of 7 bones and has a pyramidal shape, with its apex pointed posteromedially. The orbital contents comprise the eye, extraocular muscles, 5 cranial nerves, blood vessels, fat, the lacrimal apparatus, among others. Orbit and Extraocular Muscles: Anatomy)
  • Ethmoid sinus Ethmoid sinus The numerous (6-12) small thin-walled spaces or air cells in the ethmoid bone located between the eyes. These air cells form an ethmoidal labyrinth. Paranasal Sinuses: Anatomy (medial to the orbit Orbit The orbit is the cavity of the skull in which the eye and its appendages are situated. The orbit is composed of 7 bones and has a pyramidal shape, with its apex pointed posteromedially. The orbital contents comprise the eye, extraocular muscles, 5 cranial nerves, blood vessels, fat, the lacrimal apparatus, among others. Orbit and Extraocular Muscles: Anatomy)
  • Maxillary sinus Maxillary sinus The air space located in the body of the maxillary bone near each cheek. Each maxillary sinus communicates with the middle passage (meatus) of the nasal cavity on the same side. Paranasal Sinuses: Anatomy (inferior to the orbit Orbit The orbit is the cavity of the skull in which the eye and its appendages are situated. The orbit is composed of 7 bones and has a pyramidal shape, with its apex pointed posteromedially. The orbital contents comprise the eye, extraocular muscles, 5 cranial nerves, blood vessels, fat, the lacrimal apparatus, among others. Orbit and Extraocular Muscles: Anatomy)

Orbital septum:

• Membranous layer arising from the orbital periosteal lining 
• Extends into the tarsal plates of the eyelids Eyelids Each of the upper and lower folds of skin which cover the eye when closed. Blepharitis 
• Two compartments formed:
  • Preseptal: anterior to the septum
  • Postseptal: posterior to the septum
• Function: 
  • Structural support to the eye
  • Acts as a barrier preventing bacterial spread

Related 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

• Preseptal 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:
  • Infectious Infectious Febrile Infant 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 of the tissue anterior to the orbital septum
  • Involves 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 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
• Orbital 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: 
  • Infectious Infectious Febrile Infant 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 of the tissue posterior to the orbital septum
  • Involves the orbital fat, extraocular muscles, and bony structures

Epidemiology

• Preseptal 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 is more common than orbital 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.
• Both conditions are more common in children.
• 80% of cases occur in children < 10 years of age.

Etiology

Microbiology:

• 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: 
  • MSSA
  • 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
• 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 
• 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 pneumoniae
• 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 species ( sinusitis Sinusitis Sinusitis refers to inflammation of the mucosal lining of the paranasal sinuses. The condition usually occurs concurrently with inflammation of the nasal mucosa (rhinitis), a condition known as rhinosinusitis. Acute sinusitis is due to an upper respiratory infection caused by a viral, bacterial, or fungal agent. Sinusitis resulting from dental 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)
• Polymicrobial infection 
• Fungal causes: Mucorales Mucorales Mucormycosis is an angioinvasive fungal infection caused by multiple fungi within the order, Mucorales. The fungi are ubiquitous in the environment, but mucormycosis is very rare and almost always occurs in patients who are immunocompromised. Inhalation of fungal spores can cause rhinocerebral or pulmonary mucormycosis, direct inoculation can cause cutaneous mucormycosis, and ingestion can cause gastrointestinal mucormycosis. Mucorales/Mucormycosis and Aspergillus Aspergillus A genus of mitosporic fungi containing about 100 species and eleven different teleomorphs in the family trichocomaceae. Echinocandins species (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 patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship)

Pathophysiology

• Direct inoculation:
  • More common with preseptal 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
  • Mechanism:
    • Eye/eyelid trauma
    • Surgery
    • Insect/animal bites (infected)
  • Common causative pathogen: 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
• Spread from other infected structures:
  • Acute sinusitis Sinusitis Sinusitis refers to inflammation of the mucosal lining of the paranasal sinuses. The condition usually occurs concurrently with inflammation of the nasal mucosa (rhinitis), a condition known as rhinosinusitis. Acute sinusitis is due to an upper respiratory infection caused by a viral, bacterial, or fungal agent. Sinusitis:
    • Mostly ethmoiditis, as neurovascular structures penetrate the lamina papyracea and separate the ethmoid sinus Ethmoid sinus The numerous (6-12) small thin-walled spaces or air cells in the ethmoid bone located between the eyes. These air cells form an ethmoidal labyrinth. Paranasal Sinuses: Anatomy from the orbit Orbit The orbit is the cavity of the skull in which the eye and its appendages are situated. The orbit is composed of 7 bones and has a pyramidal shape, with its apex pointed posteromedially. The orbital contents comprise the eye, extraocular muscles, 5 cranial nerves, blood vessels, fat, the lacrimal apparatus, among others. Orbit and Extraocular Muscles: Anatomy
    • Main source of infection for orbital 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
    • Up to 98% of cases of orbital 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 occur with a coexisting sinusitis Sinusitis Sinusitis refers to inflammation of the mucosal lining of the paranasal sinuses. The condition usually occurs concurrently with inflammation of the nasal mucosa (rhinitis), a condition known as rhinosinusitis. Acute sinusitis is due to an upper respiratory infection caused by a viral, bacterial, or fungal agent. Sinusitis.
    • Common causative pathogen: S. pneumoniae or β-hemolytic streptococci
  • Acute dacryocystitis Acute Dacryocystitis Dacryocystitis 
  • Ear/dental 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
  • 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 ( impetigo Impetigo Impetigo is a highly contagious superficial bacterial infection typically caused by Staphylococcus aureus (most common) and Streptococcus pyogenes. Impetigo most commonly presents in children aged 2 to 5 years with lesions that evolve from papules to vesicles to pustules, which eventually break down to form characteristic “honey-colored” crusts. Impetigo, erysipelas Erysipelas Erysipelas is a bacterial infection of the superficial layer of the skin extending to the skin’s superficial lymphatic vessels. This infection presents as a raised, well-defined, tender, and bright red rash. Typically on the legs or face, but erysipelas can occur anywhere on the skin. Erysipelas)
  • Herpes simplex Herpes Simplex A group of acute infections caused by herpes simplex virus type 1 or type 2 that is characterized by the development of one or more small fluid-filled vesicles with a raised erythematous base on the skin or mucous membrane. It occurs as a primary infection or recurs due to a reactivation of a latent infection. Congenital TORCH Infections and herpes zoster Herpes Zoster Varicella-zoster virus (VZV) is a linear, double-stranded DNA virus in the Herpesviridae family. Shingles (also known as herpes zoster) is more common in adults and occurs due to the reactivation of VZV. Varicella-Zoster Virus/Chickenpox lesions
• Hematogenous Hematogenous Hepatocellular Carcinoma (HCC) and Liver Metastases spread: via blood vessels from 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

Clinical Presentation and Diagnosis

Clinical features

Preseptal and orbital 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 have common findings:

• Eyelid swelling Swelling Inflammation, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, and redness Redness Inflammation
• On occasions, eye discharge

However, orbital 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 involves 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 swelling Swelling Inflammation of the extraocular muscles and fatty tissues, which is not found in preseptal 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.

Red flags that raise suspicion for orbital 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:

• Ophthalmoplegia with diplopia Diplopia A visual symptom in which a single object is perceived by the visual cortex as two objects rather than one. Disorders associated with this condition include refractive errors; strabismus; oculomotor nerve diseases; trochlear nerve diseases; abducens nerve diseases; and diseases of the brain stem and occipital lobe. Myasthenia Gravis
• Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with eye movement
• Visual impairment
• Proptosis Proptosis Retinoblastoma

Contrasting findings

Diagnostic approach

Both conditions are usually diagnosed clinically.

Imaging studies:

CT scan with contrast:

• Confirms the diagnosis of orbital 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 in uncertain cases
• Detects complications (e.g., orbital abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease)
• Also shows opacification of the sinuses in sinusitis Sinusitis Sinusitis refers to inflammation of the mucosal lining of the paranasal sinuses. The condition usually occurs concurrently with inflammation of the nasal mucosa (rhinitis), a condition known as rhinosinusitis. Acute sinusitis is due to an upper respiratory infection caused by a viral, bacterial, or fungal agent. Sinusitis

Lab tests are generally of low diagnostic value.

• Not routine in diagnosing preseptal 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
• CBC: Leukocytosis Leukocytosis A transient increase in the number of leukocytes in a body fluid. West Nile Virus may be present in both conditions.
• Blood cultures Cultures Klebsiella: obtained in orbital 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 before administration of antibiotics
• Culture of aspirated pus and other material: 
  • Obtained from source of infection or from sinus (if concomitant sinus infection present)
  • Especially helpful 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 patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship in whom fungal and other rare etiologies can be detected

Management and Complications

Treatment of preseptal 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

• Oral antibiotics with 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
• Clindamycin Clindamycin An antibacterial agent that is a semisynthetic analog of lincomycin. Lincosamides or trimethoprim Trimethoprim The sulfonamides are a class of antimicrobial drugs inhibiting folic acid synthesize in pathogens. The prototypical drug in the class is sulfamethoxazole. Although not technically sulfonamides, trimethoprim, dapsone, and pyrimethamine are also important antimicrobial agents inhibiting folic acid synthesis. The agents are often combined with sulfonamides, resulting in a synergistic effect. Sulfonamides and Trimethoprim– sulfamethoxazole Sulfamethoxazole A bacteriostatic antibacterial agent that interferes with folic acid synthesis in susceptible bacteria. Its broad spectrum of activity has been limited by the development of resistance. Sulfonamides and Trimethoprim plus one of the following agents:
  • Amoxicillin Amoxicillin A broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration. Penicillins– clavulanic acid Clavulanic Acid A beta-lactam antibiotic produced by the actinobacterium streptomyces clavuligerus. It is a suicide inhibitor of bacterial beta-lactamase enzymes. Administered alone, it has only weak antibacterial activity against most organisms, but given in combination with other beta-lactam antibiotics it prevents antibiotic inactivation by microbial lactamase. Cephalosporins
  • Amoxicillin Amoxicillin A broad-spectrum semisynthetic antibiotic similar to ampicillin except that its resistance to gastric acid permits higher serum levels with oral administration. Penicillins
  • Cefpodoxime 
  • Cefdinir 
• Incision and drainage Incision And Drainage Chalazion of eyelid abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease
• Use 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 marker to outline erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion to evaluate progression and response to antibiotic treatment.
• Children < 1 year of age (examination can be limited) or those who are severely ill have to be treated as though they have orbital 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.
• Lack of response within 48 hours requires CT scan to evaluate for complications.

Treatment of orbital 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

• IV broad-spectrum Broad-Spectrum Fluoroquinolones antibiotics
• 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 plus one of the following medications:
  • 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
  • Cefotaxime Cefotaxime Semisynthetic broad-spectrum cephalosporin. Cephalosporins
• If there is concern for intracranial extension Extension Examination of the Upper Limbs, add anaerobic treatment ( metronidazole Metronidazole A nitroimidazole used to treat amebiasis; vaginitis; trichomonas infections; giardiasis; anaerobic bacteria; and treponemal infections. Pyogenic Liver Abscess).
• Ampicillin Ampicillin Semi-synthetic derivative of penicillin that functions as an orally active broad-spectrum antibiotic. Penicillins– sulbactam Sulbactam A beta-lactamase inhibitor with very weak antibacterial action. The compound prevents antibiotic destruction of beta-lactam antibiotics by inhibiting beta-lactamases, thus extending their spectrum activity. Combinations of sulbactam with beta-lactam antibiotics have been used successfully for the therapy of infections caused by organisms resistant to the antibiotic alone. Cephalosporins or 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: 
  • Not an initial option, as these drugs are not effective against 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 
  • Not first-line therapy, especially for intracranial extension Extension Examination of the Upper Limbs, owing to suboptimal CNS penetration Penetration X-rays 
• Response expected in 48 hours; if no improvement, imaging is done:
  • Search for complications.
  • Investigate other noninfectious Noninfectious Febrile Infant causes.
• Surgery:
  • Poor response to treatment
  • Worsening visual acuity Visual Acuity Clarity or sharpness of ocular vision or the ability of the eye to see fine details. Visual acuity depends on the functions of retina, neuronal transmission, and the interpretative ability of the brain. Normal visual acuity is expressed as 20/20 indicating that one can see at 20 feet what should normally be seen at that distance. Visual acuity can also be influenced by brightness, color, and contrast. Ophthalmic Exam
  • Intracranial extension Extension Examination of the Upper Limbs
  • Purpose:
    • Abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease drainage (especially > 10 mm MM Multiple myeloma (MM) is a malignant condition of plasma cells (activated B lymphocytes) primarily seen in the elderly. Monoclonal proliferation of plasma cells results in cytokine-driven osteoclastic activity and excessive secretion of IgG antibodies. Multiple Myeloma in diameter)
    • Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma to determine pathogen or presence of noninfectious Noninfectious Febrile Infant cause

Complications

• More common with orbital 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
• Orbital and subperiosteal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease:
  • Collection of pus involving the orbital tissue (orbital abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease) and the bony structures supporting the globe (subperiosteal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease)
  • Rapid development
  • Can result in vision Vision Ophthalmic Exam loss
• Extraorbital extension Extension Examination of the Upper Limbs:
  • Cavernous sinus thrombosis Cavernous sinus thrombosis Formation or presence of a blood clot (thrombus) in the cavernous sinus of the brain. Infections of the paranasal sinuses and adjacent structures, craniocerebral trauma, and thrombophilia are associated conditions. Clinical manifestations include dysfunction of cranial nerves III, IV, V, and VI, marked periorbital swelling, chemosis, fever, and visual loss. Cranial Nerve Palsies:
    • Rare but life-threatening
    • Superior and inferior orbital veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology drain to the cavernous sinus. 
    • Infection spreads from affected areas through valveless veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology.
    • Presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor can include facial and periorbital edema Periorbital Edema Nephrotic Syndrome in Children, ptosis Ptosis Cranial Nerve Palsies, proptosis Proptosis Retinoblastoma, chemosis Chemosis Conjunctivitis, pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with eye muscle movement, and loss of vision Vision Ophthalmic Exam.
  • Bacterial meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis: 
    • 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 of the meninges Meninges The brain and the spinal cord are enveloped by 3 overlapping layers of connective tissue called the meninges. The layers are, from the most external layer to the most internal layer, the dura mater, arachnoid mater, and pia mater. Between these layers are 3 potential spaces called the epidural, subdural, and subarachnoid spaces. Meninges: Anatomy
    • Results from hematogenous Hematogenous Hepatocellular Carcinoma (HCC) and Liver Metastases or direct spread
    • Presents with 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, 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, and signs of increased intracranial pressure Intracranial Pressure Idiopathic Intracranial Hypertension (e.g., from vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia)
    • Diagnosis by CSF studies (fluid obtained via lumbar puncture Lumbar Puncture Febrile Infant) 
    • Empiric antibiotics should be started immediately.
  • Brain abscess Brain abscess Brain abscess is a life-threatening condition that involves the collection of pus in the brain parenchyma caused by infection from bacteria, fungi, parasites, or protozoa. The most common presentation is headache, fever with chills, seizures, and neurological deficits. Brain Abscess: 
    • Suppurative lesion that may occur in one or more regions of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification
    • Caused by the direct spread of sinus, ear, or dental 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
    • Presents with 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, focal 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, signs of increased intracranial pressure Intracranial Pressure Idiopathic Intracranial Hypertension (e.g., from vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia), and focal neurologic deficits Neurologic Deficits High-Risk Headaches due to mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast effect

Differential Diagnosis

• Erysipelas Erysipelas Erysipelas is a bacterial infection of the superficial layer of the skin extending to the skin’s superficial lymphatic vessels. This infection presents as a raised, well-defined, tender, and bright red rash. Typically on the legs or face, but erysipelas can occur anywhere on the skin. Erysipelas: bacterial infection of the superficial layer 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 extending to the superficial lymphatic vessels Lymphatic Vessels Tubular vessels that are involved in the transport of lymph and lymphocytes. Lymphatic Drainage System: Anatomy within 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: Erysipelas Erysipelas Erysipelas is a bacterial infection of the superficial layer of the skin extending to the skin’s superficial lymphatic vessels. This infection presents as a raised, well-defined, tender, and bright red rash. Typically on the legs or face, but erysipelas can occur anywhere on the skin. Erysipelas presents as a raised, well-defined, tender, bright red rash Rash Rocky Mountain Spotted Fever that typically appears on the legs or face but can occur anywhere on 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. Diagnosis is based mostly on the history and physical exam. Management includes antibiotics.
• Blepharitis Blepharitis Blepharitis is an ocular condition characterized by eyelid inflammation. Anterior blepharitis involves the eyelid skin and eyelashes, while the posterior type affects the meibomian glands. Often, these conditions overlap. Blepharitis: ocular condition characterized by eyelid 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: Blepharitis Blepharitis Blepharitis is an ocular condition characterized by eyelid inflammation. Anterior blepharitis involves the eyelid skin and eyelashes, while the posterior type affects the meibomian glands. Often, these conditions overlap. Blepharitis can affect Affect The feeling-tone accompaniment of an idea or mental representation. It is the most direct psychic derivative of instinct and the psychic representative of the various bodily changes by means of which instincts manifest themselves. Psychiatric Assessment the eyelid 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, eyelashes, and meibomian glands. Blepharitis Blepharitis Blepharitis is an ocular condition characterized by eyelid inflammation. Anterior blepharitis involves the eyelid skin and eyelashes, while the posterior type affects the meibomian glands. Often, these conditions overlap. Blepharitis includes eyelid 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 with itching and redness Redness Inflammation, crusts and scales Scales Dry or greasy masses of keratin that represent thickened stratum corneum. Secondary Skin Lesions around the eyelashes, and a gritty sensation. Treatment includes warm compresses Warm Compresses Chalazion, eyelid scrubs, and topical or oral antibiotics. 
• Chalazion Chalazion A chalazion is one of the most common inflammatory lesions of the eyelid. It is caused by obstruction of the Meibomian or Zeis glands, leading to granulomatous inflammation and resulting in a firm, rubbery, slow-growing nodule that is typically non-tender. Chalazion: firm, nontender mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast at the eyelid resulting from obstruction of the Zeis or meibomian glands: Chalazion Chalazion A chalazion is one of the most common inflammatory lesions of the eyelid. It is caused by obstruction of the Meibomian or Zeis glands, leading to granulomatous inflammation and resulting in a firm, rubbery, slow-growing nodule that is typically non-tender. Chalazion is usually managed conservatively with warm compresses Warm Compresses Chalazion. Persistence of the lesion requires incision and curettage Curettage A scraping, usually of the interior of a cavity or tract, for removal of new growth or other abnormal tissue, or to obtain material for tissue diagnosis. It is performed with a curet (curette), a spoon-shaped instrument designed for that purpose. Benign Bone Tumors or glucocorticoid injection by an ophthalmologist.
• Hordeolum Hordeolum A hordeolum is an acute infection affecting the meibomian, Zeiss, or Moll glands of the eyelid. Stasis of the gland secretions predisposes to bacterial infection. Staphylococcus aureus is the most common pathogen. Hordeolum (Stye): localized infection arising from the gland of Zeis, gland of Moll Gland of Moll Blepharitis, or meibomian gland Meibomian Gland Chalazion: 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 is a common cause of hordeola. Findings of a tender, erythematous, pus-filled nodule Nodule Chalazion help establish the diagnosis. Management is generally conservative, though severe cases may require antibiotics or drainage. Chalazia, on the other hand Hand The hand constitutes the distal part of the upper limb and provides the fine, precise movements needed in activities of daily living. It consists of 5 metacarpal bones and 14 phalanges, as well as numerous muscles innervated by the median and ulnar nerves. Hand: Anatomy, are due to sterile Sterile Basic Procedures, granulomatous inflammation Granulomatous Inflammation Chalazion and are not painful.