Otitis can affect the inner or outer parts of the ear. The condition can be:

• Acute ear infection -- Starts suddenly and lasts for a short period of time. It is often painful.
• Chronic ear infection -- Occurs when the ear infection does not go away or keeps coming back. It may cause long-term damage to the ear.

Based on location otitis can be:

• Otitis externa (swimmer's ear) -- Involves the outer ear and ear canal. A more severe form can spread into the bones and cartilage around the ear.
• Otitis media (ear infection) -- Involves the middle ear, which is located just behind the eardrum.
• Otitis media with effusion -- Occurs when there is thick or sticky fluid behind the eardrum in the middle ear, but there is no ear infection.

Ear infection; Infection - ear

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Pelton SI. Otitis externa, otitis media, and mastoiditis. In: Bennett JE, Dolin R, Blaser MJ, eds. Mandell, Douglas, and Bennett's Principles and Practice of Infectious Diseases. 9th ed. Philadelphia, PA: Elsevier; 2020:chap 61.

Pham LL, Bourayou R, Maghraoui-Slim V, Kone-Paut I. Otitis, sinusitis and related conditions. In: Cohen J, Powderly WG, Opal SM, eds. Infectious Diseases. 4th ed. Philadelphia, PA: Elsevier; 2017:chap 26.

Updated by: Charles I. Schwartz, MD, FAAP, Clinical Assistant Professor of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, General Pediatrician at PennCare for Kids, Phoenixville, PA. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.