Loose anagen hair syndrome: an underdiagnosed condition in males.

Loose anagen hair syndrome (LAHS) is a condition of sparse, short hair that is easily and painlessly extracted from the scalp. Since it was first described in the 1980s, it is considered a rare, sporadic condition found predominantly in females. Since then, there have been multiple reports of LAHS occurring in families, suggesting an autosomal dominant inheritance pattern may also be present. An autosomal dominant trait would suggest a more equal sex ratio. We report a case of a boy diagnosed with LAHS and propose that it may be underdiagnosed in males simply because of hairstyle differences between boys and girls.