Hypertrichosis (also known as Werewolf syndrome) is the presence of abnormal amounts of hair on the body in non-androgenic sensitive areas. This needs to be differentiated from hirsutism, which is a condition associated with male-like pattern growth of hair in females, mostly due to endocrine causes.
Excess hair growth associated with hypertrichosis may include any hair type (terminal, vellus, and lanugo), this hair growth particularly involves non-androgenic sensitive areas. Congenital form of hypertrichosis is believed to be due to inheritance or a spontaneous mutation. In addition, this form of hypertrichosis is extremely rare, and only a few cases have ever been reported. Furthermore, hypertrichosis could also be acquired and presents in late stages of cancer by an unknown mechanism, this hair growth is termed “malignant down”. However, cancer is not the only cause of the acquired form, it can also be caused by certain medications, such as minoxidil, phenytoin, and cyclosporine. There is not a known cure for the congenital form of hypertrichosis, however, the mainstay of treatment for the acquired form is addressing the culprit and using cosmetic hair removal methods (shaving, waxing, eflornithine cream, etc.).
Hypertrichosis is a rare disorder that presents with excessive unwanted hair growth. It could be congenital or acquired, however, the congenital is very rare. Treatment involves treating the underlying cause and using hair removal techniques.
Written by: Khalid Al Dakheel, Medical Student
Fitzpatrick’s Color Atlas and Synopsis of Clinical Dermatology, Seventh Edition