This site is intended for health professionals only

At the heart of general practice since 1960

Otitis externa - evidence based management

Latest in the series offering evidence-based advice not covered by official guidelines

Latest in the series offering evidence-based advice not covered by official guidelines

Basic rules

• Use effective topical medication.

• Inform the patient about factors causing or exacerbating the condition.

• Consider malignancies and malignant external otitis as a cause of prolonged inflammation.

• Predisposing factors:

– avoid incubating water in the ear canal (acute diffuse external otitis is common in summer)

– a hot and humid climate

– atopy and other allergies, seborrhoeic eczema and other skin diseases, some systemic diseases (such as diabetes) and some psychosocial problems

– chronic, sometimes acute, otitis media

–may also be associated with skin infections such as erysipelas and herpes zoster.

Investigations

History

• Duration and earlier recurrences.

• Self-manipulation of the ear canal preceding the symptoms, other injuries and water in the ear canal.

• Systemic diseases.

• Medicines and cosmetic preparations applied in the ear or its surroundings these can be the cause of external otitis.

Clinical findings

• In acute otitis externa the skin of the ear canal is red, moist, swollen and very tender. Sometimes a small abscess is present in the outer part of the ear canal. The tympanic membrane may not be visible because of massive swelling of the ear canal skin.

• In chronic inflammation the skin of the ear canal is not tender but itching is the main symptom. Skin is thickened and scaly.

Clinical examination

• Clean the ear canal – possible foreign bodies, scaling and secretions should be removed mechanically with care.

• Rinse the ear canal with hand-warm saline (not in a perforated ear) and dry it.

• Examine the tympanic membrane to detect chronic or acute otitis media. A pneumatic otoscope is necessary. Tuning fork tests are often useful.

Laboratory and radiological investigations

• Differentiation between acute, fulminant otitis externa and mastoiditis may be difficult.

• In acute infection, gram-positive cocci are usually predominant. Gram-negative rods and sometimes fungi are also detected in chronic infection. In fungal otitis externa the ear canal may seem mouldy and covered by a grey membrane. Bacterial or fungal cultures are only indicated in prolonged, chronic cases.

Treatment

• Thorough and frequent cleaning of the ear canal (rinsing with saline and drying thereafter) is the most important treatment for otitis externa.

• An ethanol-water (30:70) solution can be used to rinse a seborrhoeic ear canal.

• A severely swollen ear canal can be treated with a tampon infiltrated with a topical preparation. An antibiotic-steroid solution or 3% borate in spirit are suitable (level of evidence = B).

• If no tampon is needed, topical eardrops are prescribed.

• An abscess in the ear canal can be incised, with a tympanocentesis lancet using topical lidocaine as an anaesthetic.

Topical medication

• Topical preparations should be selected according to common dermatological principles: wet for acute inflammation, greasy for chronic inflammation. A low-pH ointment is beneficial.

• Preparations used should be simple to avoid contact allergy. Topical neomycin and bacitracin should especially be avoided.

• Only use topical antifungal preparations in confirmed fungal infections.

• A local steroid preparation is the best treatment for itching and swelling of the ear canal skin.

Systemic drugs

• NSAIDs can be used in acute inflammation.

• Systemic antimicrobials are usually not indicated.

• Recurrent or chronic external otitis:

– advise the patient to avoid manipulating ear canals

– prescribe a steroid ointment to alleviate the itch.

• Water should be avoided (showering or swimming without protecting the ear canal). Patients with frequent recurrences should always avoid water in the ear canal.

Indications for specialist consultation

• Chronic or recurrent otitis externa despite microbiological investigations and therapeutic trials.

• Granulation tissue in the ear canal may be a sign of malignant otitis externa.

• Unilateral otitis externa in the elderly may be a symptom of a malignant tumour. Refer to a specialist if response is poor.

This synopsis is taken from EBM Guidelines, a collection of treatment and diagnosis guidelines supported by evidence summaries.

© Duodecim Medical Publications. Distributed by Wiley-Blackwell.

For more information, email freynold@wiley.co.uk or visit ebmg.wiley.com

Otitis externa

Rate this article 

Click to rate

  • 1 star out of 5
  • 2 stars out of 5
  • 3 stars out of 5
  • 4 stars out of 5
  • 5 stars out of 5

0 out of 5 stars

Have your say