Otitis externa (swimmers ear) is an infection of the external ear canal. Glands within the ear canal produce a layer of protective cerumen (ear wax). If too little ear wax is produced, the skin of the canal is less protected and hence more predisposed to infection. If too much ear wax is produced, the excessive wax may cause retention of water and debris, also leading to increase ear infections, especially if the water has a high bacteria content (pond, lake, ocean, hot tub). In some cases, normal ear canals can become infected with bacteria, fungus, or other infectious agents. In some instances, systemic disease can cause otitis externa.
Otitis externa is generally quite easy to treat, however it can lead to serious complications in individuals who are diabetic or immunocompromised. Otitis externa is defined as chronic when the duration of the infection exceeds four weeks or when more than four episodes occur in 1 year.
Acute infection can be very painful and needs immediate attention. Individuals who are prone to otitis externa are advised to either use ear plugs in association with all water exposure including baths/showers, or to use ear drying drops or an ear drying device after any exposure to water.