Human werewolf syndrome or hypertrichosis.

As the name suggests, this medical condition causes excessive hair growth anywhere on a person's body. It can affect both male and females, but is extremely rare. The abnormal hair growth may cover the face and body, or be in small patches on certain parts of the body. Hypertrichosis can appear at birth or develop over time.

It is said that hypertrichosis usually produces one of three types of hair: the first is vellus: they may be located anywhere but the soles of a person's feet, back of ears, around lips and palms, or on scar tissue. Second is lanugo, which is soft and fine, like that on the body of a new-born baby. The third is called terminal, in which the hair is long and thick, and usually very dark.

The causes of...