Ear itching

Ear itching (aural pruritus) is an itch in the external canal or concha. Most cases arise from canal skin disease: otitis externa, eczema, seborrhoeic dermatitis, dry canal skin or fungal infection.

Mechanisms. Inflammation of canal skin, loss of the acid mantle and cerumen barrier, contact allergy, fungal or bacterial overgrowth, and neuropathic itch.

Classification. Infective (bacterial, fungal), dermatological (eczema, seborrhoeic dermatitis, psoriasis, contact dermatitis), mechanical (cotton buds, hearing aids, earplugs, water), middle ear origin (chronic suppurative otitis media), and systemic or neuropathic.

Key distinctions. Itch with little pain suggests eczema or fungal disease. Pain on pulling the pinna suggests bacterial otitis externa. Itch with discharge and perforation suggests middle ear disease.

History. Duration, laterality, relation to water, humidity, hearing aids, earplugs, headphones, cotton bud or hairpin use, and ear drops used. Ask about discharge, pain, hearing loss, tinnitus, skin disease elsewhere (scalp, face, flexures), atopy, nickel or fragrance allergy, diabetes, and previous ear surgery.

Drug history. Neomycin, framycetin and other topical antibiotics (contact allergy), prolonged topical antibiotic or steroid use (fungal overgrowth), and systemic drugs causing generalised itch (opioids, antimalarials).

Examination. Pinna and post-auricular skin (redness, scaling, fissures), canal by otoscopy (swelling, dryness, scale, debris, fungal hyphae, wet newspaper appearance), tympanic membrane (perforation, retraction), scalp, face and flexures for seborrhoeic dermatitis, psoriasis or eczema, and the other ear.

Red flags

• Severe pain or swollen canal in diabetes or immunosuppression (malignant otitis externa)
• Bloody discharge, granulation, ulcer or non-healing lesion in an adult (cancer)
• Facial weakness, hearing loss or vertigo
• Perforation with persistent discharge
• Vesicles on the pinna or canal

Special groups. Children: eczema, swimming related otitis externa, foreign body. Pregnancy: use topical treatment; avoid oral ciprofloxacin and doxycycline. Region specific: otomycosis is common in humid climates.

Canal skin disease

• Acute and chronic otitis externa
• Otomycosis (Aspergillus, Candida)
• Eczema (atopic, asteatotic), seborrhoeic dermatitis, psoriasis
• Contact dermatitis from topical drops, hearing aids, earplugs, metals, cosmetics
• Dry canal skin, absent cerumen, keratosis obturans

Middle ear and other

• Chronic suppurative otitis media with discharge, cholesteatoma
• Foreign body, impacted wax
• Herpes zoster oticus (early)
• Squamous cell and basal cell carcinoma of the canal (rare)

Systemic and neuropathic

• Generalised itch from cholestasis, uraemia, thyroid disease, iron deficiency, lymphoma
• Neuropathic itch, anxiety and habitual scratching

Reasoning. Clinical examination usually gives the diagnosis. Swab and biopsy only for failure of treatment or atypical findings.

First line. Otoscopy with suction toilet, examination of skin elsewhere, and tuning forks. Glucose in diabetes or recurrent infection.

Targeted tests. Swab for culture and fungal microscopy in discharging or treatment resistant ears. Patch testing for suspected contact allergy (neomycin, framycetin, fragrance, nickel, rubber, hearing aid acrylic). Biopsy for any persistent ulcer or granulation in the canal. For generalised itch: full blood count, ferritin, urea, creatinine, liver function, thyroid stimulating hormone, glucose, and chest radiograph when lymphoma is suspected.

Limitations. Swab cultures may grow colonisers. Patch tests need dermatology interpretation.

All patients. Keep the ear dry, no cotton buds or other objects, no irrigation with a perforation, and remove debris by gentle dry mopping or microsuction.

Otitis externa. Acetic acid 2 percent spray or drops, 5 drops three times daily for 7 days for mild disease with an intact drum. Ciprofloxacin 0.3 percent with dexamethasone 0.1 percent ear drops, 4 drops twice daily for 7 days for moderate disease, which is safe with a perforation. Avoid neomycin, framycetin and gentamicin containing drops with a perforation.

Otomycosis. Debris removal and clotrimazole 1 percent solution, 4 drops three times daily for at least 14 days (evidence is limited).

Eczema and seborrhoeic dermatitis. Hydrocortisone 1 percent ointment applied thinly to canal skin twice daily for 7 days, then reduced; emollient to the pinna; ketoconazole 2 percent shampoo to the scalp twice weekly for seborrhoeic dermatitis. Stop the offending contact allergen.

Dry canal skin. Sparing use of olive oil or emollient drops, 2 drops once or twice daily, and avoidance of soap in the canal.

Systemic causes. Treat the cause: cholestatic itch with colestyramine 4 g orally once or twice daily, maximum 16 g daily, separated from other drugs by at least 1 hour before or 4 to 6 hours after.

Monitoring. Review at 2 weeks. Persistent itch beyond 4 weeks needs ENT or dermatology review and biopsy of any lesion.

Referral and escalation. Same day for suspected malignant otitis externa. ENT within 2 weeks for granulation, ulcer or suspected tumour. Dermatology for suspected contact allergy or resistant eczema.

Admission criteria. Malignant otitis externa, or severe cellulitis of the pinna with systemic illness.

Discharge and safety netting. Keep the ear dry. Return for pain, discharge, hearing loss, facial weakness, vertigo or no improvement in 2 weeks.