Hypertrichosis

Abstract

Localized changes of hair are also important in the diagnosis of some dermatological diseases like in the case of elemantary lesions. The ear consists of hair follicles in different parts, and overgrowth of hair may be present in some congenital and acquired entities. Ear hypertrichosis may be a feature of diseases causing diffuse hypertrichosis, or may be an isolated finding. In the latter case, there may be an association with underlying tumoral lesions, or the presentation solely bases on overgrowth of hair. Increased hairs may be of lanugo type (fine, soft, unmedullated, light-coloured) or terminal type (thick, medullated, pigmented). Hairy pinna is a variation of human hair with age (Figs. 19.1, 19.2). It usually becomes evident in the third or fourth decade and almost exclusively affects men. There is a possible hereditary tendency. Coarse terminal hairs typically grow on tragus bilaterally. Some patients have hypertrichosis, especially on the lower part of the helix and some in both localizations. This type of hypertrichosis does not generally have any underlying cause but it poses a cosmetic problem. On the other hand, some AIDS patients may show acquired hairy pinna in addition to eyelash trichomegaly.