Otitis externa

Bottom Line

• Scanty white/yellowish discharge associated with an oedematous ear canal is otitis externa.
• Pain often builds up over a couple of days and is increased on moving the pinna or pressing on the tragus.
• Increased risk with exposure to water e.g. recent holidays, swimming lessons.
• Treatment is with TOPICAL antibiotics (usually drops) and regular analgesia.

What is otitis externa?

It is acute inflammation and infection of the skin of the external auditory canal.

It might be localized, like a pimple, or more often is diffuse, involving all the skin of the ear canal. It might extend to involve the pinna, causing perichondritis, or infection of the side of the face, cellulitis or erysipelas.

Who gets it?

This condition is less common in children than acute otitis media, but certain conditions can predispose an individual to get this condition including:

• Eczema, involving the skin of/near the ear
• Psoriasis
• Water exposure: recent holidays, regular swimming, frequent baths
• Trauma, particularly from cleaning ears with cotton buds
• Immunocompromised patients

What are the most common pathogens?

Otitis externa might be caused by bacterial, fungal or viral infections.

What are the clinical findings?

Patients will find it painful when you touch the pinna or if you push on the tragus. The ear canal is swollen and oedematous, to the point that it closes up in severe cases. White debris or yellowish discharge can be seen in the ear canal.

Signs of mucous, however, indicate a discharge from the mucosa in the middle ear, indicating a tympanic membrane perforation is present. In this case, the patient should be treated for AOM.

The patient will have reduced hearing. As the ear canal closes over from the swelling a conductive hearing loss develops.

How should I treat it?

If you can see into the ear canal, enough to see the discharge, then firstly treat with

TOPICAL antimicrobial agents: antiseptic  e.g acetic acid drops/spray, antibiotic e.g. aminoglycoside or fluoroquinolones (ciprofloxacin) drops

Steroids: topical – usually combined with the above drops.

Analgesia: this is a very painful condition – paracetamol/NSAIDS

If the canal is closed over, refer the patient to ENT for further management. This is likely to include micro-suction clearance of the ear canal debris and/or insertion of a dressing (wick) into the ear, onto which antimicrobial therapy can be instilled.

Side effects of the treatment

Aminoglycosides carry a risk of ototoxicity: the use of these agents is not advised if it is known that there is a tympanic membrane perforation.

Aminoglycosides, especially neomycin, can cause contact dermatitis in 15% of patients.

License for use of fluoroquinolone

Though the use of topical ciprofloxacin in the ear canal is licensed in the US and many countries worldwide, it is not licensed for this use in the UK. Despite this many clinicians, in the UK, will choose to prescribe this medication ‘off license‘; but in doing so should follow the published guidance of the General Medical Council, UK.

What are the other possible diagnoses?

In children, the most likely diagnosis is going to be AOM, with a TM perforation, so that the ear discharge has caused a secondary OE. In this case, the discharge will be mucoid (stringy) in consistency.

Selected references

Kaushik V, Malik T, Saeed S R. Interventions to treat acute otitis externa. Cochrane Database Syst Rev 2010;(1):CD004740

Marais J, Rutka J A. Ototoxicity and topical eardrops. Clin Otolaryngol Allied Sci 1998;23:360-367

GMC. Good practice in prescribing and managing medicines and devices.

About Sinéad Davis

Sinéad graduated from UCC, Ireland and moved to Wales to pursue her career in ENT. Working as an ENT consultant in Swansea, Wales since 2007 and has a special interest in Otology and Medical Education, in particular clinical bedside teaching.

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