Trichodynia: a review of the literature.

Trichodynia designates a painful sensation on the scalp sometimes reported by patients with hair loss. Its best description dates back to 1960, when Sulzberger et al. (Arch Dermatol 1960; 81: 556-560) reported it in a proportion of women complaining of an unexplained diffuse alopecia. Sulzberger et al.'s remark that trichodynia may also be circumscribed ("spotty") is an important detail missed by most ensuing observers. Women are mostly affected or, at least, more likely to report it. The quality and intensity vary greatly, the "burning" variety being most severe. Whether trichodynia is prevalent in telogen effluvium or it may also be present in androgenetic alopecia remains a crucial question. Hairs shed only from painful sites, and this observation suggests that the severity of trichodynia is directly related to hair shedding and intensity. Trichodynia seems to be related to the release of substance P and is present in alopecia areata. Both observations suggest that peripilar inflammation may be a causative agent.