Otitis externa (“swimmers ear”) is an inflammation of the outer ear and ear canal. Along with otitis media, external otitis is one of the two human conditions commonly called “earache”. It also occurs in many other species. Inflammation of the skin of the ear canal is the essence of this disorder. The inflammation can be secondary to dermatitis (eczema) only, with no microbial infection, or it can be caused by active bacterial or fungal infection. In either case, but more often with infection, the ear canal skin swells and may become painful and/or tender to touch.
When the physician looks in the ear, the canal appears red and swollen in well-developed cases of acute external otitis. The ear canal may also appear eczema-like, with scaly shedding of skin. Touching or moving the outer ear increases the pain, and this maneuver on physical exam is very important in establishing the clinical diagnosis. It may be difficult for the physician to see the eardrum with an otoscope at the initial examination because of narrowing of the ear canal from inflammation and the presence of drainage and debris. Culture of the drainage may identify the bacteria or fungus causing infection, but it is not part of the routine diagnostic evaluation.
The goal of treatment is to cure the infection and to return the ear canal skin to healthy condition. When external otitis is very mild, in its initial stages, simply refraining from swimming or washing hair for a few days and keeping all implements out of the ear, usually result in a cure. Topical solutions or suspensions in the form of ear drops are the mainstays of treatment for external otitis. Some contain antibiotics, either antibacterial or antifungal, and others are designed to mildly acidify the ear canal environment to discourage bacterial growth. Some prescription drops also contain anti-inflammatory steroids, which help to resolve swelling and itching. Removal of debris (wax, shed skin, and pus) from the ear canal promotes direct contact of the prescribed medication with the infected skin and shortens recovery time.