Hair and systemic disease

Hair loss (alopecia) occurs as a manifestation of numerous systemic disease s, but usually can be categorized into one of five general groups: telogen effluvium, anagen arrest, follicular destruction, hair miniaturization, and hair shaft defects. An excess of hair also can be evidence of internal dis ease, and there are two general categories of increased hair density: hyper trichosis and hirsutism. The basic categories of hair disease and the syste mic conditions associated with them are discussed. The history, physical ex amination, and histopathologic data usually are sufficient to categorize th e form of hair disorder and may provide a clue to the nature of the underly ing systemic disease.