Localized trichorrhexis nodosa.

Trichorrhexis nodosa is a disorder of the hair shaft in which there is a distinctive response to injury. The hair is fragile and on examination regularly spaced pale 'node-like' swellings may be observed. It may affect normal hair following excessive or repeated trauma, or may occur after minimal trauma if there is an inherent defect in keratin synthesis causing abnormally brittle hair. The diagnosis can be readily made clinically and confirmed microscopically. Treatment is aimed at reducing trauma. We describe a case of localized trichorrhexis nodosa in a patient with otherwise apparently normal hair.