Otitis externa, also called swimmer's ear, is inflammation of the ear canal. It often presents with ear pain, swelling of the ear canal, and occasionally decreased hearing. Typically there is pain with movement of the outer ear. A high fever is typically not present except in severe cases.
Otitis externa may be acute (lasting less than six weeks) or chronic (lasting more than three months). Acute cases are typically due to bacterial infection, and chronic cases are often due to allergies and autoimmune disorders. Risk factors for acute cases include swimming, minor trauma from cleaning, using hearing aids and ear plugs, and other skin problems, such as psoriasis and dermatitis. People with diabetes are at risk of a severe form of malignant otitis externa. Diagnosis is based on the signs and symptoms. Culturing the ear canal may be useful in chronic or severe cases.
Acetic acid ear drops may be used as a preventive measure. Treatment of acute cases is typically with antibiotic drops, such as ofloxacin or acetic acid. Steroid drops may be used in addition to antibiotics. Pain medications such as ibuprofen may be used for the pain. Antibiotics by mouth are not recommended unless the person has poor immune function or there is infection of the skin around the ear. Typically, improvement occurs within a day of the start of treatment. Treatment of chronic cases depends on the cause.
Otitis externa affects 1–3% of people a year; more than 95% of cases are acute. About 10% of people are affected at some point in their lives. It occurs most commonly among children between the ages of seven and twelve and among the elderly. It occurs with near equal frequency in males and females. Those who live in warm and wet climates are more often affected.