Otitis Externa (Clinical)

Overview

Definition

Otitis externa Otitis externa Otitis externa (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss. Otitis Externa is an infection of the external auditory canal External Auditory Canal Otitis Externa.

Epidemiology^[1,6,7,9,11]

• 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: 4 of 1000 people annually in the United States 
• Approximately 10% of people develop otitis externa Otitis externa Otitis externa (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss. Otitis Externa in their lifetime.
• Age:
  • Occurs in all age groups
  • Most common in children
• More likely to occur in the summer because of:
  • Humidity
  • Participation in water activities

Etiology^[1,6,7,9,11]

• Bacterial infection (most cases):
  • Pseudomonas aeruginosa Pseudomonas aeruginosa A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. Aeruginosa is a major agent of nosocomial infection. Pseudomonas 
  • 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
  • Staphylococcus epidermidis Staphylococcus epidermidis A species of staphylococcus that is a spherical, non-motile, gram-positive, chemoorganotrophic, facultative anaerobe. Mainly found on the skin and mucous membrane of warm-blooded animals, it can be primary pathogen or secondary invader. Staphylococcus
  • Proteus vulgaris Proteus vulgaris A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in soil, fecal matter, and sewage. It is an opportunistic pathogen and causes cystitis and pyelonephritis. Proteus
  • 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
• Fungal infection (rare):
  • Candida albicans Candida albicans A unicellular budding fungus which is the principal pathogenic species causing candidiasis (moniliasis). Candida/Candidiasis
  • Aspergillus Aspergillus A genus of mitosporic fungi containing about 100 species and eleven different teleomorphs in the family trichocomaceae. Echinocandins niger

Risk factors^[1,6,7,9,11]

• Swimming or other water exposure
• Hot, humid weather
• Trauma (including cleaning with cotton swabs)
• Ear canal occlusion:
  • Cerumen Cerumen The yellow or brown waxy secretions produced by vestigial apocrine sweat glands in the external ear canal. Otitis Externa
  • Foreign body Foreign Body Foreign Body Aspiration
  • Hearing aids AIDS Chronic HIV infection and depletion of CD4 cells eventually results in acquired immunodeficiency syndrome (AIDS), which can be diagnosed by the presence of certain opportunistic diseases called AIDS-defining conditions. These conditions include a wide spectrum of bacterial, viral, fungal, and parasitic infections as well as several malignancies and generalized conditions. HIV Infection and AIDS
  • Headphones
• Dermatologic conditions:
  • Eczema Eczema Atopic dermatitis, also known as eczema, is a chronic, relapsing, pruritic, inflammatory skin disease that occurs more frequently in children, although adults can also be affected. The condition is often associated with elevated serum levels of IgE and a personal or family history of atopy. Skin dryness, erythema, oozing, crusting, and lichenification are present. Atopic Dermatitis (Eczema)
  • Contact dermatitis Contact dermatitis A type of acute or chronic skin reaction in which sensitivity is manifested by reactivity to materials or substances coming in contact with the skin. It may involve allergic or non-allergic mechanisms. Male Genitourinary Examination
  • Psoriasis Psoriasis Psoriasis is a common T-cell-mediated inflammatory skin condition. The etiology is unknown, but is thought to be due to genetic inheritance and environmental triggers. There are 4 major subtypes, with the most common form being chronic plaque psoriasis. Psoriasis
• Radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma therapy
• Immunosuppression:
  • HIV HIV Anti-HIV Drugs/ AIDS AIDS Chronic HIV infection and depletion of CD4 cells eventually results in acquired immunodeficiency syndrome (AIDS), which can be diagnosed by the presence of certain opportunistic diseases called AIDS-defining conditions. These conditions include a wide spectrum of bacterial, viral, fungal, and parasitic infections as well as several malignancies and generalized conditions. HIV Infection and AIDS
  • 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
  • Chemotherapy Chemotherapy Osteosarcoma

Pathophysiology

Defense mechanisms Defense mechanisms Defense mechanisms are normal subconscious means of resolving inner conflicts between an individual’s subjective moral sense and their thoughts, feelings, or actions. Defense mechanisms serve to protect the self from unpleasant feelings (anxiety, shame, and/or guilt) and are divided into pathologic, immature, mature, neurotic, and other types. Defense Mechanisms of the ear^[1,9,11]

• Tragus Tragus Otitis Externa and conchal cartilage Conchal Cartilage Otitis Externa → prevent the entrance of foreign bodies
• Hair follicles and isthmus Isthmus Uterus, Cervix, and Fallopian Tubes: Anatomy narrowing → stop the entry of contaminants
• Cerumen Cerumen The yellow or brown waxy secretions produced by vestigial apocrine sweat glands in the external ear canal. Otitis Externa → creates an acidic environment → inhibits bacterial and fungal growth

Pathogenesis of otitis externa Otitis externa Otitis externa (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss. Otitis Externa^[1,9,11]

• Breakdown 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– cerumen Cerumen The yellow or brown waxy secretions produced by vestigial apocrine sweat glands in the external ear canal. Otitis Externa barrier is caused by:
  • Damage to epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology
  • ↓ Quantity and quality Quality Activities and programs intended to assure or improve the quality of care in either a defined medical setting or a program. The concept includes the assessment or evaluation of the quality of care; identification of problems or shortcomings in the delivery of care; designing activities to overcome these deficiencies; and follow-up monitoring to ensure effectiveness of corrective steps. Quality Measurement and Improvement of cerumen Cerumen The yellow or brown waxy secretions produced by vestigial apocrine sweat glands in the external ear canal. Otitis Externa
  • Moisture accumulation
  • Obstruction of the ear canal
• ↑ pH pH The quantitative measurement of the acidity or basicity of a solution. Acid-Base Balance of the ear canal → ear canal becomes a prime breeding ground for microscopic organisms → infection
• 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 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 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 → purulent exudate Exudate Exudates are fluids, cells, or other cellular substances that are slowly discharged from blood vessels usually from inflamed tissues. Pleural Effusion

Clinical Presentation and Diagnosis

Symptoms^[1,6,7,9,11]

• Ear pain Ear Pain Acute Otitis Media
• Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema)
• Fullness
• Discharge ( otorrhea Otorrhea Otitis Externa)
• Hearing loss Hearing loss Hearing loss, also known as hearing impairment, is any degree of impairment in the ability to apprehend sound as determined by audiometry to be below normal hearing thresholds. Clinical presentation may occur at birth or as a gradual loss of hearing with age, including a short-term or sudden loss at any point. Hearing Loss

Physical examination^[1,6,7,9,11]

• Tenderness with tragal pressure 
• Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways with manipulation of the auricle
• 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 and 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 ear canal
• Yellow, white, gray, or brown purulent debris
• On pneumatic otoscopy Pneumatic Otoscopy Otitis Externa, the tympanic membrane Tympanic membrane An oval semitransparent membrane separating the external ear canal from the tympanic cavity. It contains three layers: the skin of the external ear canal; the core of radially and circularly arranged collagen fibers; and the mucosa of the middle ear. Ear: Anatomy is mobile.

Diagnosis

The diagnosis of otitis externa Otitis externa Otitis externa (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss. Otitis Externa is based on the history and physical examination. Culture of the ear canal or discharge is indicated for severe, recurrent, or chronic cases.

Severity of Disease^[16]

• Mild disease:
  • Minor discomfort and pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema)
  • Minimal canal erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion
• Moderate disease:
  • Intermediate degree of pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways (on movement of auricle and tragal pressure) and pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema)
  • Partial occlusion of the ear canal due to 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 (especially in the thicker, lateral canal
  • Seropurulent secretions
• Severe disease:
  • Intense pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
  • Edematous occlusion of ear canal
  • Possible auricular/ periauricular cellulitis Periauricular Cellulitis Otitis Externa, regional 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, and 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

Management

Management may vary based on practice location. The following information is based on US and European guidelines.

• Remove cerumen Cerumen The yellow or brown waxy secretions produced by vestigial apocrine sweat glands in the external ear canal. Otitis Externa, desquamated 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 purulent material.
• Protect ear from water.
• Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways relief:^[14]
  • Ibuprofen Ibuprofen A nonsteroidal anti-inflammatory agent with analgesic properties used in the treatment of rheumatism and arthritis. Nonsteroidal Antiinflammatory Drugs (NSAIDs):
    • Children: 4–10 mg/kg orally every 6–8 hours when required; maximum dose: 40 mg/kg/day 
    • Adults: 200–400 mg orally every 4–6 hours when required; maximum dose: 3.2 g/day
  • Acetaminophen Acetaminophen Acetaminophen is an over-the-counter nonopioid analgesic and antipyretic medication and the most commonly used analgesic worldwide. Despite the widespread use of acetaminophen, its mechanism of action is not entirely understood. Acetaminophen
    • Children: 10–15 mg/kg orally or rectally every 4–6 hours when required; maximum dose: 75 mg/kg/day 
    • Adults: 325–650 mg orally every 4–6 hours when required; maximum dose: 4 g/day
  • 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
    • Use only for severe pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
    • Use only after other analgesics have been exhausted
• Topical antibiotic otic drops, proper administration of which involves the following:^[13]
  • An ear wick can be placed to facilitate medication delivery in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with significant ear canal 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.
  • Lie down with the affected side up.
  • Run otic solution alongside the ear canal until full.
  • Gently move the pinna to eliminate air pockets.
  • Remain in this position for 3‒5 minutes and leave the canal open to dry.
  • 60% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship self-administer drops inappropriately; it may be helpful for another individual to administer drops.
• Otomycosis is a fungal infection of the external auditory canal External Auditory Canal Otitis Externa:
  • Can develop with the bacterial infection, or can result from antibiotic therapy
  • Treat with topical antifungals (e.g., clotrimazole Clotrimazole An imidazole derivative with a broad spectrum of antimycotic activity. It inhibits biosynthesis of the sterol ergostol, an important component of fungal cell membranes. Its action leads to increased membrane permeability and apparent disruption of enzyme systems bound to the membrane. Azoles solution)

Treatment approach (intact tympanic membrane Tympanic membrane An oval semitransparent membrane separating the external ear canal from the tympanic cavity. It contains three layers: the skin of the external ear canal; the core of radially and circularly arranged collagen fibers; and the mucosa of the middle ear. Ear: Anatomy)

Medications used depend on the severity of infection.^[12–14,16]

• Mild infection:
  • Otic antimicrobial options:
    • Acetic acid 2%
    • Acetic acid 2%/ hydrocortisone Hydrocortisone The main glucocorticoid secreted by the adrenal cortex. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions. Immunosuppressants 1%
    • Neomycin/polymyxin B/ hydrocortisone Hydrocortisone The main glucocorticoid secreted by the adrenal cortex. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions. Immunosuppressants
  • Typical duration of therapy: 7–10 days
• Moderate infection:
  • Beyond mild infection, an otic fluoroquinolone antibiotic is recommended:
    • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones 0.2%
    • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones 0.2%/ hydrocortisone Hydrocortisone The main glucocorticoid secreted by the adrenal cortex. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions. Immunosuppressants 1%
    • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones 0.3%/ dexamethasone Dexamethasone An anti-inflammatory 9-fluoro-glucocorticoid. Antiemetics 0.1% 
    • Ofloxacin Ofloxacin A synthetic fluoroquinolone antibacterial agent that inhibits the supercoiling activity of bacterial DNA gyrase, halting DNA replication. Fluoroquinolones 0.3%
  • Typical duration of therapy: 7–10 days
• Severe infection:
  • Includes those with uncontrolled DM DM 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, HIV HIV Anti-HIV Drugs, or 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 state
  • Culture ear canal to guide definitive antibiotic treatment. 
  • Treat with any of the above fluoroquinolone otic drops, plus 1 of the following systemic antibiotics for 7–10 days:^[15]
    • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones
    • Levofloxacin Levofloxacin The l-isomer of ofloxacin. Fluoroquinolones
    • Cefuroxime
    • 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–clavulanate

Treatment approach (perforated tympanic membrane Tympanic membrane An oval semitransparent membrane separating the external ear canal from the tympanic cavity. It contains three layers: the skin of the external ear canal; the core of radially and circularly arranged collagen fibers; and the mucosa of the middle ear. Ear: Anatomy)^[12,13]

• Includes the presence of tympanostomy tubes Tympanostomy Tubes Acute Otitis Media
• Culture ear canal to guide definitive antibiotic treatment. 
• Medications:
  • Avoid ototoxic ear drops (those that contain aminoglycosides Aminoglycosides Aminoglycosides are a class of antibiotics including gentamicin, tobramycin, amikacin, neomycin, plazomicin, and streptomycin. The class binds the 30S ribosomal subunit to inhibit bacterial protein synthesis. Unlike other medications with a similar mechanism of action, aminoglycosides are bactericidal. Aminoglycosides and alcohol).
    • Aminoglycoside preparations include tobramycin, gentamicin Gentamicin Aminoglycosides, and neomycin.
    • Aminoglycoside use can lead to hearing loss Hearing loss Hearing loss, also known as hearing impairment, is any degree of impairment in the ability to apprehend sound as determined by audiometry to be below normal hearing thresholds. Clinical presentation may occur at birth or as a gradual loss of hearing with age, including a short-term or sudden loss at any point. Hearing Loss.
    • Alcohol and acidifying solutions irritate the middle ear Middle ear The space and structures directly internal to the tympanic membrane and external to the inner ear (labyrinth). Its major components include the auditory ossicles and the eustachian tube that connects the cavity of middle ear (tympanic cavity) to the upper part of the throat. Acute Otitis Media mucosa.
  • Use ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones– dexamethasone Dexamethasone An anti-inflammatory 9-fluoro-glucocorticoid. Antiemetics, ofloxacin Ofloxacin A synthetic fluoroquinolone antibacterial agent that inhibits the supercoiling activity of bacterial DNA gyrase, halting DNA replication. Fluoroquinolones, and ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones otic preparations (as above).
  • If ear drops are not tolerated, give oral antibiotics.
  • Modify antibiotics when culture results are available.

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas^[12,13,15]

• Symptom improvement begins about 36–48 hours after initiation of treatment.
• Completely resolves in about 6 days

Prevention^[2,12]

• Remove obstructing cerumen Cerumen The yellow or brown waxy secretions produced by vestigial apocrine sweat glands in the external ear canal. Otitis Externa
• Use earplugs while swimming.
• Apply acidifying ear drops:
  • Before swimming 
  • After swimming 
  • At bedtime
• Dry ear canal with a hair dryer.
• Avoid trauma to the ear canal.
• Avoid inserting towels, cotton swabs, or other foreign objects into the ear canal.
• Remove hearing aids AIDS Chronic HIV infection and depletion of CD4 cells eventually results in acquired immunodeficiency syndrome (AIDS), which can be diagnosed by the presence of certain opportunistic diseases called AIDS-defining conditions. These conditions include a wide spectrum of bacterial, viral, fungal, and parasitic infections as well as several malignancies and generalized conditions. HIV Infection and AIDS nightly, and clean them regularly.

Malignant otitis externa Malignant Otitis Externa Otitis Externa

Also known as necrotizing otitis externa Otitis externa Otitis externa (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss. Otitis Externa, this is an invasive, life-threatening infection of the external auditory canal External Auditory Canal Otitis Externa and 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 base.

Etiology:^[12]

• Almost always caused by Pseudomonas aeruginosa Pseudomonas aeruginosa A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. Aeruginosa is a major agent of nosocomial infection. Pseudomonas (>90%)
• Risk factors:
  • Elderly
  • 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
  • HIV HIV Anti-HIV Drugs
• Along with above risk factors, the condition is more frequently seen in individuals with a prior history of ear irrigation.

Clinical presentation:^[10,12,17]

• Extreme otalgia Otalgia Acute Otitis Media (disproportionate to findings) and otorrhea Otorrhea Otitis Externa
  • Significant pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways unresponsive to topical measures
  • Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways can extend to the temporomandibular joint.
• Granulation Granulation Wound Healing tissue may be visible in the inferior portion of the external auditory canal External Auditory Canal Otitis Externa.
• Can lead to cranial nerve palsies Cranial Nerve Palsies Cranial nerve palsy is a congenital or acquired dysfunction of 1 or more cranial nerves that will, in turn, lead to focal neurologic abnormalities in movement or autonomic dysfunction of its territory. Head/neck trauma, mass effect, infectious processes, and ischemia/infarction are among the many etiologies for these dysfunctions. Diagnosis is initially clinical and supported by diagnostic aids. Management includes both symptomatic measures and interventions aimed at correcting the underlying cause. Cranial Nerve Palsies (especially 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 VII, IX, XI, XII) if the disease progresses to osteomyelitis Osteomyelitis Osteomyelitis is an infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous). Infections are most commonly caused by Staphylococcus aureus. Osteomyelitis 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 base and temporomandibular joint

Diagnosis:^[10,12,19]

• Cultures of ear canal drainage
• ↑ CRP, ESR ESR Soft Tissue Abscess
• CT scan:
  • Preferred initial imaging
  • Bony erosion Erosion Partial-thickness loss of the epidermis Generalized and Localized Rashes
  • Middle ear Middle ear The space and structures directly internal to the tympanic membrane and external to the inner ear (labyrinth). Its major components include the auditory ossicles and the eustachian tube that connects the cavity of middle ear (tympanic cavity) to the upper part of the throat. Acute Otitis Media radiolucency Radiolucency Chondrosarcoma
• MRI:
  • Helpful in determining extent of infection
  • Also useful in determining presence of intracranial extension Extension Examination of the Upper Limbs
• Biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma to rule out malignancy Malignancy Hemothorax (e.g., squamous cell carcinoma Squamous cell carcinoma Cutaneous squamous cell carcinoma (cSCC) is caused by malignant proliferation of atypical keratinocytes. This condition is the 2nd most common skin malignancy and usually affects sun-exposed areas of fair-skinned patients. The cancer presents as a firm, erythematous, keratotic plaque or papule. Squamous Cell Carcinoma (SCC) of the temporal bone Temporal bone Either of a pair of compound bones forming the lateral (left and right) surfaces and base of the skull which contains the organs of hearing. It is a large bone formed by the fusion of parts: the squamous (the flattened anterior-superior part), the tympanic (the curved anterior-inferior part), the mastoid (the irregular posterior portion), and the petrous (the part at the base of the skull). Jaw and Temporomandibular Joint: Anatomy)

Management:^[12,17]

• Patient should be admitted to the hospital.
• Otolaryngology consult
• Culture ear canal discharge to determine definitive antibiotic treatment.
• IV antibiotic therapy (empiric treatment with antipseudomonal coverage):
  • Ciprofloxacin Ciprofloxacin A broad-spectrum antimicrobial carboxyfluoroquinoline. Fluoroquinolones
    • Note: About 50% of P. aeruginosa P. aeruginosa A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. Aeruginosa is a major agent of nosocomial infection. Pseudomonas 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 show 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 fluoroquinolones Fluoroquinolones Fluoroquinolones are a group of broad-spectrum, bactericidal antibiotics inhibiting bacterial DNA replication. Fluoroquinolones cover gram-negative, anaerobic, and atypical organisms, as well as some gram-positive and multidrug-resistant (MDR) organisms. Fluoroquinolones so use other options if 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 rate is high.
  • 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
  • Ceftazidime Ceftazidime Semisynthetic, broad-spectrum antibacterial derived from cephaloridine and used especially for pseudomonas and other gram-negative infections in debilitated patients. Cephalosporins
  • Cefepime Cefepime A fourth-generation cephalosporin antibacterial agent that is used in the treatment of infections, including those of the abdomen, urinary tract, respiratory tract, and skin. It is effective against pseudomonas aeruginosa and may also be used in the empiric treatment of febrile neutropenia. Cephalosporins
  • 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
• 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 rarely needed for extensive infection.
• Monitoring and treatment duration:^[18]
  • Transition to oral antibiotics when patient exhibits:
    • Clinical response
    • ↓ Inflammatory markers
  • MRI and/or gallium citrate (Ga-67) scanning can be used to follow disease activity.
  • Treatment course generally lasts for 6–8 weeks.

Complications:^[10,12]

• Cranial nerve palsies Cranial Nerve Palsies Cranial nerve palsy is a congenital or acquired dysfunction of 1 or more cranial nerves that will, in turn, lead to focal neurologic abnormalities in movement or autonomic dysfunction of its territory. Head/neck trauma, mass effect, infectious processes, and ischemia/infarction are among the many etiologies for these dysfunctions. Diagnosis is initially clinical and supported by diagnostic aids. Management includes both symptomatic measures and interventions aimed at correcting the underlying cause. Cranial Nerve Palsies
• 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 
• 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 abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease
• Dural sinus thrombophlebitis
• 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 base osteomyelitis Osteomyelitis Osteomyelitis is an infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous). Infections are most commonly caused by Staphylococcus aureus. Osteomyelitis

Differential Diagnosis

• Contact dermatitis Contact dermatitis A type of acute or chronic skin reaction in which sensitivity is manifested by reactivity to materials or substances coming in contact with the skin. It may involve allergic or non-allergic mechanisms. Male Genitourinary Examination: Persistent 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 and 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 ear canal and auricle despite adequate otitis externa Otitis externa Otitis externa (also known as external otitis or swimmer’s ear) is an infection of the external auditory canal that is most often caused by acute bacterial infection and is frequently associated with hot, humid weather and water exposure. Patients commonly present with ear pain, pruritus, discharge, and hearing loss. Otitis Externa treatment can indicate an allergic reaction. This reaction can be caused by ototopical medication, cosmetics, or shampoos. Pruritus Pruritus An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief. Atopic Dermatitis (Eczema) and erythema Erythema Redness of the skin produced by congestion of the capillaries. This condition may result from a variety of disease processes. Chalazion are the primary symptoms, and vesicles Vesicles Female Genitourinary Examination can be seen, usually due to rubbing and itching. The diagnosis is made clinically. Management involves cessation of the causative substance.
• Chronic suppurative otitis media: a complication of persistent acute otitis media Acute Otitis Media Acute otitis media is an infection in the middle ear characterized by mucosal inflammation and retention of fluid. The most common pathogens are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. The condition can present with fever, otalgia, and diminished hearing. Acute Otitis Media with perforation Perforation A pathological hole in an organ, blood vessel or other soft part of the body, occurring in the absence of external force. Esophagitis. Symptoms include otorrhea Otorrhea Otitis Externa, otalgia Otalgia Acute Otitis Media, hearing loss Hearing loss Hearing loss, also known as hearing impairment, is any degree of impairment in the ability to apprehend sound as determined by audiometry to be below normal hearing thresholds. Clinical presentation may occur at birth or as a gradual loss of hearing with age, including a short-term or sudden loss at any point. Hearing Loss, tinnitus Tinnitus A nonspecific symptom of hearing disorder characterized by the sensation of buzzing, ringing, clicking, pulsations, and other noises in the ear. Objective tinnitus refers to noises generated from within the ear or adjacent structures that can be heard by other individuals. The term subjective tinnitus is used when the sound is audible only to the affected individual. Tinnitus may occur as a manifestation of cochlear diseases; vestibulocochlear nerve diseases; intracranial hypertension; craniocerebral trauma; and other conditions. Cranial Nerve Palsies, or vertigo Vertigo Vertigo is defined as the perceived sensation of rotational motion while remaining still. A very common complaint in primary care and the ER, vertigo is more frequently experienced by women and its prevalence increases with age. Vertigo is classified into peripheral or central based on its etiology. Vertigo. The diagnosis is made clinically.  The tympanic membrane Tympanic membrane An oval semitransparent membrane separating the external ear canal from the tympanic cavity. It contains three layers: the skin of the external ear canal; the core of radially and circularly arranged collagen fibers; and the mucosa of the middle ear. Ear: Anatomy is often partially visible and not movable by pneumatic insufflation. A tympanic membrane perforation Tympanic membrane perforation A temporary or persistent opening in the eardrum (tympanic membrane). Clinical signs depend on the size, location, and associated pathological condition. Acute Otitis Media or retraction pockets may also be seen. Management primarily involves topical fluoroquinolones Fluoroquinolones Fluoroquinolones are a group of broad-spectrum, bactericidal antibiotics inhibiting bacterial DNA replication. Fluoroquinolones cover gram-negative, anaerobic, and atypical organisms, as well as some gram-positive and multidrug-resistant (MDR) organisms. Fluoroquinolones. 
• Carcinoma of the ear canal: a rare disease to be considered in the presence of an abnormal growth or unresponsiveness to usual treatment. Common symptoms of carcinoma of the ear canal include mild pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways and bloody otorrhea Otorrhea Otitis Externa. A friable lesion with surrounding purulence on an otoscopic exam may be seen. Hearing loss Hearing loss Hearing loss, also known as hearing impairment, is any degree of impairment in the ability to apprehend sound as determined by audiometry to be below normal hearing thresholds. Clinical presentation may occur at birth or as a gradual loss of hearing with age, including a short-term or sudden loss at any point. Hearing Loss and facial paralysis are late signs. Diagnosis is made clinically and confirmed by biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. 
• Psoriasis Psoriasis Psoriasis is a common T-cell-mediated inflammatory skin condition. The etiology is unknown, but is thought to be due to genetic inheritance and environmental triggers. There are 4 major subtypes, with the most common form being chronic plaque psoriasis. Psoriasis: an inflammatory 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 condition that commonly involves the external ear canal and leads to redness Redness Inflammation and scaling that often extends to the conchal bowl and auricle: The clinical appearance of psoriasis Psoriasis Psoriasis is a common T-cell-mediated inflammatory skin condition. The etiology is unknown, but is thought to be due to genetic inheritance and environmental triggers. There are 4 major subtypes, with the most common form being chronic plaque psoriasis. Psoriasis in the external auditory canal External Auditory Canal Otitis Externa varies by subtype. The diagnosis is made clinically.  Management can include steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors and retinoids Retinoids Retinol and derivatives of retinol that play an essential role in metabolic functioning of the retina, the growth of and differentiation of epithelial tissue, the growth of bone, reproduction, and the immune response. Dietary vitamin A is derived from a variety of carotenoids found in plants. It is enriched in the liver, egg yolks, and the fat component of dairy products. Fat-soluble Vitamins and their Deficiencies. More severe cases may require high-dose steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors, light therapy, or biologics.