Inflammatory diseases of the external ear. Non-inflammatory diseases of the external ear.
A. Inflammatory disease of the external ear
1. Definition: Acute Otitis Externa (“Swimmer’s ear”) is an acute, diffuse bacterial infection and inflammation of the skin and subcutaneous tissue of the external auditory canal.
2. Etiopathogenesis:
- Etiology:
- Primarily Bacteria, most commonly Pseudomonas aeruginosa (90% of cases) and Staphylococcus aureus.
- excessive moisture (swimming/humidity)
- trauma (cotton swabs, scratching)
- Skin diseases: eczema, psoriasis
- Pathogenesis: Disruption of the protective skin-cerumen barrier which facilitates bacterial invasion.
3. Classification
- 1. Diffuse acute OE (most common)
- 2. Furunculosis (localized OE → infected hair follicle)
- 3. Chronic OE (>3 months)
- 4. Eczematous / allergic OE
- 5. Malignant (necrotizing) otitis externa – life-threatening osteomyelitis of skull base (diabetics). Cranial nerve ivolv, IV antiiotics.
4. Clinical Picture
Symptoms
- Severe ear pain (otalgia), which is very tender with manipulation of the tragus or pinna traction.
- May present with otorrhea (discharge), pruritus (itching), aural fullness and conductive hearing loss due to canal swelling and debris.
5. Paraclinical & Radiological Exams
- Paraclinical:
- Otoscopy: main diagnostic tool
- Swab for culture if severe, recurrent or non-responsive
- Radiological: Not typically needed unless progression to Malignant Otitis Externa is suspected.
- CT temporal bone: if malignant OE suspected
- MRI: to evaluate skull base spread
6. Treatment
- Aural Toilet/Debridement: Gentle, thorough cleaning of the canal debris.
- Topical Therapy (First-Line): Acetic acid drops (to restore acidic pH) or Antibiotic/Corticosteroid ear drops (eg, fluoroquinolones like Ciprofloxacin, or polymyxin B/neomycin/hydrocortisone).
- Ear Wick: Used if canal edema prevents drop penetration.
- Systemic Antibiotics: Reserved for cellulitis extending beyond the EAC or immunocompromised patients.
- Malignant OE - IV anti-pseudomonal antibiotics (ciprofloxacin), Strict glycemic control, Long-term therapy
7. Complications
- Chronic otitis externa
- Perichondritis
- Malignant OE → skull base osteomyelitis
- Facial nerve palsy
8. Differential Diagnosis
- Acute otitis media with otorrhea (TM perforation)
- Eczema/psoriasis of EAC
- Foreign body
- Furunculosis
- Herpes zoster oticus (Ramsay Hunt)
2. Perichondritis / chondritis of the ear
1. Definition: Painful bacterial infection of the perichondrium or cartilage of the auricle, typically sparing the lobule.
2. Etiopathogenesis
- Trauma, piercing
- Burns
- Surgery
- Pseudomonas aeruginosa most common pathogen
3. Classification
- Acute perichondritis
- Suppurative chondritis
4. Clinical Picture
- Pain, redness, and significant swelling of the pinna, often sparing the earlobe (which lacks cartilage).
- If untreated, can lead to cartilage necrosis and "Cauliflower Ear"deformity.
5. Investigations
- Clinical diagnosis
- Culture if abscess/purulent discharge
6. Treatment
- IV anti-pseudomonal antibiotics (ciprofloxacin)
- Incision and drainage if abscess
- Remove foreign bodies (piercing)
7. Complications
- Cartilage necrosis
- Ear deformity (“cauliflower ear”)