Acquired Disorders of Hair
Hair is a defining feature of mammals. In other species hair confers important functions that affect survival. Most have been lost or are irrelevant in humans but the role of hair in social and sexual signalling in women and in men survives and thrives. Departures from cultural norms, either physiological or due to pathology, can therefore cause much concern and anxiety. Following an introduction to hair biology, this chapter considers the approach to the diagnosis and management of the patient with hair loss before discussing specific hair disorders. These include the various forms of hair loss due to hair follicle pathology, disturbances in hair cycling and hair shaft dystrophies, and disorders associated with excessive hair growth. The chapter concludes with a discussion of acquired alterations in hair pigmentation.
Keywords alopecia, androgenetic alopecia, cicatricial alopecia, telogen effluvium, hair, hair pigmentation, alopecia areata, hirsutism, hair dystrophy, hair cosmetics