[Peripilar keratin casts]

The hair casts are infrequent condition. There are two distinct groups: idiopathic and secondary. Idiopathic hair casts are described in three girls aged 3, 5 and 13 years. They are cousins, indicating a possible hereditary influence. It's a illness without systemic affection, with pathophysiology yet unknown. It is important to know, overall for differential diagnosis, specially nits. The only treatment is removal of casts by careful and repeated combing.