Werewolf syndrome (Hypertrichosis or Ambras syndrome)
As rare as they come, hypertrichosis has an incidence rate of about one in a billion people. Yes, that’s right – it’s so rare that there have been only 50 or so documented cases worldwide.
Characterized by prolific and/or excessive hair growth on every inch of skin, it was coined as the “werewolf syndrome”, in reference to the legends of men turning into wolves. It is caused by a genetic mutation that impacts upon the distribution of hair follicles and their growth.
In the womb, as hair follicles begin to form, each one produces a unique chemical message, which is transmitted throughout its surrounding area. This chemical message prevents other hair follicles from crowding it, leaving a fine and even distribution of hair over a particular surface.
For those with hypertrichosis, however, the message gets lost in translation, meaning that hair follicles crop up in every place they can, cramming each square inch full of hair. Sometimes even more than one hair sprouts from a single hair follicle. This gives them the appearance of literally being covered by hair.
There is not yet a known cure for hypertrichosis, though the condition can be somewhat managed in the short term by cutting or shaving, and by chemical or laser removal treatments.