External Otologic Infections

Otitis externa is an infection and inflammation involving the external auditory canal and may include the auricle and tympanic membrane. It is characterized by otorrhea, canal inflammation, otalgia, pruritus, tinnitus, and hearing loss. It is frequently caused by acute bacterial infections but can also be attributed to chronic bacterial inflammation, fungal infections, myringitis, or viral infections. The differential diagnosis includes otitis media, malignant otitis externa, neoplasm, and autoimmune or dermatologic conditions. Treatment includes topical medications (e.g., topical antibiotics, antiseptics, and corticosteroids), aural toilet, and in some cases surgical debridement. It is important to recognize the underlying diagnosis and common pathogens to appropriately treat the disease. In addition, the integrity of the tympanic membrane must be considered, as many topical medications are potentially ototoxic. This chapter reviews the etiology, clinical features, diagnosis, and treatment of various external otologic infections.