What is otitis externa?

Otitis externa is an inflammation of the external ear canal, which frequently becomes infected by commensal bacteria (Pseudomonas and Proteus). Digital contamination of the inflamed ear from other body sites may result in secndary infection with Staph, aureus and coliforms.

The inflammation results in an exquisitely itchy and uncomfortable ear with redness and serious discharge. Systemic symptoms and fever are rare. Infection may spread to the pinna and skin around the ear resulting in a perichondritis of the pinna and local cellulitis.

What are the important factors associated with otitis externa?

Water: An episode of acute otitis externa will often follow a holiday abroad with lots of swimming, regular swimming in a pool, regular showering after sports activities, a trip to the hairdressers or ear syringing

Cleaning the ears: Those who use cotton buds, car keys, matches, etc, to try and clear the ear of the wax, cause irritation to the skin by local trauma. The protective waxy layer is damaged and the skin is traumatised

Generalised skin conditions: Those with severe eczema, psoriasis and other skin conditions are more prone to problems of otitis externa as part of their skin disease

Hearing aids and ear-pieces Local irritation and condensation in the ear canal may result from the regular use of ear-pieces and hearing-aid moulds. Occasionally, a skin sensitivity to the acrylic in the hearing aid mould may develop.

What are the typical features and symptoms of otitis externa?

How should otitis externa be treated in primary care?

Prevention: Avoid syringing ears where there is a history of otitis externa or infection following previous syringing.

Keep the ears dry: Give advice to avoid cleaning the ears with buds, wet flannels etc. The ear skin is migratory and self-cleaning. “Never put anything smaller than your elbow in your ear!”

Prevent water contamination: For those prone to otitis externa, it is worth investing in silicone customised swimmers ear moulds. These can be made to fit, usually by a private hearing aid dispenser, and some NHS hearing aid clinics will supply them for a charge.

Drug Therapy: There is almost always an element of both inflammation and infection. For very mild cases, you may get away with just water protection and an astringent spray such as “Ear Calm” (OTC), which contains acetic acid (a mild antibacterial/antifungal). For more severe cases, where the skin is soggy, a steroid/antibiotic combination that also contains an astringent may be more useful (eg Otomize). For dry, flaky skin, an oily steroid/antibiotic combination is more appropriate (e.g. “Locorten-Vioform”). Where there is a discharge with the inflammation, a stronger antibiotic/steroid combination is needed (e.g. “Sofradex” or “Otosporin”). Gentamicin-based products should be avoided as it is used systematically for serious infections. Chloramphenicol should also be avoided as local skin sensitivity reactions are common

Treat the pinna: If necessary, treat the pinna at the edge of the ear with a topical anti-inflammatory ointment (eg “Triadcortyl-otic”). This can be applied to the bowl of the ear (the concha) each night.

Analgesia: The pain may be intense and require a combination of analgesics to control it adequately (e.g. paracetemol, codeine, diclofenac).