Dermatologic diseases of the external ear.

The external ear is composed of the auricle (pinna) and the external auditory canal. Both of these structures contain elastic cartilage (except the earlobe) and a small amount of subcutaneous fat, which are covered by skin. The skin of the cartilaginous canal contains hair cells, sebaceous (lipid-producing) glands, and apocrine (ceruminous) glands; this is in contrast with the osseous canal, which contains neither glands nor hair follicles. The auricle is susceptible to environmental influences and trauma. Due to its exposed locale, the ear is particularly vulnerable to the effects of ultraviolet light and, consequently, to preneoplastic and neoplastic skin lesions. The ear also has a sound-receiving function and a location that is both visible and aesthetically obvious, thereby drawing considerable attention from the patient. Dermatologic diseases on the external ear are seen in a variety of medical disciplines. Dermatologists, otorhinolaryngologists, family practitioners, and general and plastic surgeons are regularly consulted about cutaneous lesions on the ear. These lesions can be grouped into three main categories: (1) infectious; (2) tumoral; and (3) noninfectious inflammatory. The purposes of this contribution are to review various dermatologic diseases of the external ear and to update current diagnosis and treatment information related to these conditions.