Otitis Externa Disease

BASICS

DESCRIPTION

Inflammation of the external auditory canal

  • Acute diffuse otitis externa - the most common form, an infectious process usually bacterial, occasionally fungal
  • Acute circumscribed otitis externa - synonymous with furuncle. Associated with infection of the hair follicle.
  • Chronic otitis externa - same as acute diffuse, but of longer duration (greater than 6 weeks)
  • Eczematous otitis externa - may accompany typical atopic eczema or other primary skin conditions
  • Necrotizing "malignant" otitis externa - an infection which extends into the deeper tissues adjacent to the canal. May include osteomyelitis and cellulitis. Rare in children.
  • System(s) affected: Skin/Exocrine
  • Genetics: N/A
  • Incidence/Prevalence in USA:
    • Unknown; incidence is higher in the summer months
    • Acute, chronic, and eczematous - common
    • Necrotizing - uncommon
  • Predominant age: All ages
  • Predominant sex: Male = Female
SIGNS AND SYMPTOMS
  • Itching
  • Plugging of the ear
  • Otalgia
  • Periauricular adenitis
  • Erythematous canal
  • Purulent discharge
  • Eczema of pinna
  • Cranial nerve involvement (VII, IX–XII)
CAUSES
  • Acute diffuse otitis externa
    • Traumatized external canal (e.g., from use of cotton tip swab)
    • Bacterial infection - pseudomonas (67% cases); staphylococcus; streptococcus; gram negative rods
    • Fungal infection - aspergillus (90% cases); Phycomycetes; Rhizopus; actinomyces; Penicillium; yeast
  • Chronic otitis externa
    • Bacterial infection - Pseudomonas
  • Eczematous otitis externa (associated with primary skin disorder)
    • Eczema
    • Seborrhea
    • Neurodermatitis
    • Contact dermatitis
    • Purulent otitis media
    • Sensitivity to topical medications
  • Necrotizing otitis externa
    • Invasive bacterial infection - Pseudomonas
RISK FACTORS
  • Acute and chronic otitis externa
    • Traumatization of external canal
    • Swimming
    • Hot humid weather
    • Use of a hearing aid
  • Eczematous
    • Primary skin disorder
  • Necrotizing otitis externa in adults
    • Elderly
    • Diabetes mellitus
    • Debilitating disease
  • Necrotizing otitis externa in children (rare)
    • Leukopenia
    • Malnutrition
    • Diabetes mellitus
    • Diabetes insipidus

DIAGNOSIS

LABORATORY

Gram stain and culture of canal discharge (occasionally helpful)
Drugs that may alter lab results: Antibiotic pretreatment
Disorders that may alter lab results: N/A

PATHOLOGICAL FINDINGS
  • Acute and chronic otitis externa - desquamation of superficial epithelium of external canal with infection
  • Eczematous otitis externa - pathologic findings consistent with primary skin disorder, secondary infection on occasion
  • Necrotizing otitis externa - vasculitis, thrombosis and necrosis of involved tissues; osteomyelitis
SPECIAL TESTS
N/A
IMAGING
Radiologic evaluation of deep tissues in necrotizing otitis externa
DIAGNOSTIC PROCEDURES

N/A

TREATMENT

APPROPRIATE HEALTH CARE

Outpatient, except for resistant cases and necrotizing otitis externa

GENERAL MEASURES
  • Thorough cleansing of external canal
  • Narcotic analgesics
  • Antipruritic and antihistamines (eczematous form)
  • 'Ear wick' (Pope) for nearly occluded ear canal
SURGICAL MEASURES

N/A

ACTIVITY

No restrictions

DIET

No restrictions

PATIENT EDUCATION

Discuss Prevention/Avoidance

FOLLOW UP

PREVENTION/AVOIDANCE
  • Avoid prolonged exposure to moisture
  • Utilize preventive antiseptics
  • Treat predisposing skin conditions
  • Eliminate self-inflicted trauma to canal
  • Diagnose and treat underlying systemic conditions
POSSIBLE COMPLICATIONS
  • Mainly a problem with necrotizing otitis externa. May spread to infect contiguous bone and CNS structures.
  • Acute otitis externa may spread to pinna causing a chondritis
EXPECTED COURSE AND PROGNOSIS
  • Acute otitis externa - rapid response to therapy with total resolution
  • Chronic otitis externa - with repeated cleansing and antibiotic therapy the majority of cases will resolve. Occasionally, surgical intervention is required for resistant cases.
  • Eczematous otitis externa - resolution will occur with control of the primary skin condition
  • Necrotizing otitis externa - can usually be managed with debridement and prolonged parenteral antibiotics. Recurrence rate is 100% when treatment is inadequate. Surgical intervention may be necessary in resistant cases or if there is cranial nerve involvement. Mortality rate is significant, probably secondary to the underlying disease.

MISCELLANEOUS

ASSOCIATED CONDITIONS

See Risk Factors

AGE-RELATED FACTORS

N/A
Pediatric: N/A
Geriatric: N/A
Others: N/A

PREGNANCY

N/A

OTHER NOTES

N/A

ABBREVIATIONS

N/A

Clinical Investigations

ROLE OF HOMOEOPATHY

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