Also known as otitis externa, it’s a bacterial, fungal, or allergic inflammation of the skin and subcutis (tissue beneath the dermis) in the outer ear canal. In some cases, it can cause myringitis (an infection of the tympanic membrane or eardrum).

Inflammation of the ear canal can cause an itching sensation, followed by extreme earache, especially when chewing or tucking at the outer ear. You may notice swelling and either a watery or a dry, flaky discharge. This can lead to a blockage of the ear canal and hearing difficulty. In rare cases, it can spread to bone tissue at the base of the skull and affect the surrounding cranial nerves.

A frequent trigger is a microtrauma or minor damage to the skin inside your ear—caused by, for example, cleaning your ears with a cotton swab. Shampoo, hairspray, soap and other irritants can trigger an allergic reaction and cause inflammation.

Other risk factors include chronic middle ear infection, abnormal bone growth in the ear canal and diseases like neurodermatitis, psoriasis, and diabetes.

Your hearing aids can also be the culprit. Hearing aid wearers should take extra care to keep their ears free from dirt and moisture, and clean their hearing aids often to get rid of any bacteria. When you are fitted with hearing aids, the audiologist should go over the cleaning procedure and you should follow that procedure every week to prevent infections.

Generally, the first step is to examine the ear canal to determine if there’s an abscess or boil and to note the presence of any pain. If necessary, a specialist will clean the ear canal and may perform a smear and/or hearing test. People who use hearing aids are advised to get suitable treatment and wait for the infection to clear before wearing their devices again.

A specialist will start by cleaning the ear canal. The infection is usually treated conservatively with ear drops or creams, to reduce swelling and restore hearing. In some cases, the specialist may prescribe a round of antibiotics.