Ear Canal Dermatitis

Ear canal dermatitis is eczematous inflammation of the skin of the external ear canal, caused by allergy, irritants, seborrhoea or atopy, and it is a common cause of chronic itching and recurrent otitis externa.

• Types: atopic dermatitis, seborrhoeic dermatitis, allergic contact dermatitis (neomycin and other topical drops, nickel in earrings and hearing aids, fragrances, hair products), and irritant dermatitis (water, soap, cotton buds).
• It leads to dry, flaky skin that is easily infected.
• Chronic scratching and cleaning cause trauma and secondary bacterial or fungal infection.
• It occurs in children with eczema and in adults with seborrhoeic dermatitis or psoriasis.

Itch is the dominant symptom.

• Intense itching of the ear canal, with a dry, flaky or scaly canal and occasional weeping.
• Mild discomfort, a feeling of fullness, and mild hearing loss from debris.
• Redness, fissuring and oedema of the canal skin; scaling of concha and pinna; scaly rash behind the ear.
• Other sites of dermatitis (scalp, face, flexures) may be present.
• Differential diagnosis: otitis externa (bacterial or fungal), psoriasis, tinea, herpes zoster, foreign body, cholesteatoma, malignancy and neurodermatitis.
• Complications: secondary bacterial or fungal infection, canal stenosis, chronic otitis externa, hearing loss and sleep disturbance.

Diagnosis is clinical.

• Otoscopy: dry, scaly, erythematous canal; look for tympanic membrane perforation.
• Examine skin elsewhere (scalp, eyebrows, nasolabial folds, flexures).
• Swab for culture if infection is suspected.
• Patch testing for suspected allergic contact dermatitis (neomycin, nickel, fragrance, preservatives).
• Microscopy and culture for fungus.

Stop irritants, soothe and treat inflammation.

• Supportive: avoid scratching, cotton buds and water exposure, stop suspected allergen (change earrings, hearing aid material, stop topical drops), use dry ear precautions when washing hair, and use emollients on the outer ear.
• Pharmacological: topical corticosteroid, for example hydrocortisone 1 percent or betamethasone 0.1 percent ointment or drops, applied thinly to the canal once or twice daily for 1 to 2 weeks (only when drum is intact). Combination steroid-antibiotic drops (for example ciprofloxacin and dexamethasone) if infection coexists.
• Seborrhoeic dermatitis: ketoconazole 2 percent shampoo or cream twice weekly, with a mild topical steroid.
• Atopic dermatitis: emollients, and tacrolimus 0.03 to 0.1 percent ointment as a steroid-sparing agent.
• Antihistamine at night for itch: cetirizine 10 mg (adults; 5 mg ages 2 to 6 years) daily.
• Secondary bacterial infection: topical ciprofloxacin 0.3 percent drops 3 to 5 drops three times daily for 7 days. Fungal infection: clotrimazole 1 percent drops three times daily for 2 weeks.
• Procedures: aural toilet by micro-suction.
• Special groups: children with eczema need coordinated skin care. Patients with perforated drums should avoid ototoxic drops (aminoglycosides).
• Red flags: severe pain, discharge not responding to treatment, facial weakness, unilateral persistent lesion (to exclude cancer) and diabetes.
• Follow-up: review at 2 weeks. Refer to dermatology for patch testing or ENT if persistent or ulcerated.