Loose anagen syndrome.

A distinctive new hair condition, the loose anagen syndrome, features anagen hairs that are loosely anchored and easily pulled from the scalp. The children studied had sparse hair that did not grow long and that pulled easily from the scalp. The majority of patients were blond girls, aged 2 to 5 years, but both sexes and those with dark hair can be affected. The hair was not fragile, and easily pulled hairs were misshapen anagen hairs without external root sheaths. Histologic examination of the hair showed abnormal premature keratinization of Huxley's and Henle's layers of the inner root sheath in some samples. Length and density of hair gradually increased with age, but anagen hairs remained loosely anchored in adulthood. This report describes findings in 22 children and five adults with the loose anagen syndrome.