For centuries, people have documented and depicted human werewolves with great interest. Legends and modern movies characterize these werewolves with fangs, hairy bodies, and danger, but are werewolves just the stuff of legends? Actually, these stories are probably referring to people who suffer from werewolf syndrome, or congenital hypertrichosis lanuginosa (CHL).

Entertained by Werewolves

The big reason you don’t hear about everyday cases of hypertrichosis is that it’s not a common condition. In fact, scientists have documented less than 100 cases worldwide, making it a hard one to study and understand.


The first reported case of werewolf syndrome goes as far back as 1556. Petrus Gonzales of the Canary Islands was born with an abnormally hairy face and body, and his appearance intrigued people in his era.

Gonzales’s condition drew so much curiosity that it brought him to the courts of King Henry II where he became a type of entertainment. Eventually, Gonzales did get married and have two children, both of whom also inherited the skin anomaly.

Throughout their lives, the family continued to draw much curiosity, traveling throughout Europe and making several appearances in kingly courts. Many early cases of CHL repeat such a story, traveling as entertainers individually or with circuses.


Modern Cases

While you might not see many cases of werewolf syndrome, some people do still get it today. One mother and her three children recently received treatment in Nepal for the condition. While most people with CHL show signs from birth, the excessive hair growth didn’t show up in this family until later on.

Devi, the concerned mother, wanted her little family to get treatment so that they could all return to a normal life. With hypertrichosis, people treated the children differently, teasing them about their appearance.

How It Happens

Only in modern years have scientists spotted a probable cause for such a condition. Researchers attribute excessive localized or full-body hair growth to a genetic mutation. In 1995, researchers studied the cause of CHL in a Mexican family and found an approximate location for the mutation: the X chromosome.

Then, researchers tested a Chinese man with the condition and found that he actually had extra genes on this chromosome. After more testing, researchers confirmed this mutation in the Mexican family as well. Still, scientists don’t have an explanation for the reason behind such a mutation.

In addition, people can develop werewolf syndrome later in life, as in the case of the Nepal family. Some factors that may trigger the condition include malnutrition, light sensitivity, and cancer. As far as is known, CHL does not cause major health problems apart from the excessive hair.


The hair, called lanugo, also has specific characteristics. Commonly, doctors and parents see this soft hair on newborn babies, but lanugo usually sheds after a short time.

For people with werewolf syndrome, the lanugo does not shed and continues growing on the baby’s body. The skin problem might stay localized in one part of the body or grow excessively all over. Also, those with the syndrome may have hearing problems, glaucoma, and some skeletal abnormalities.

For now, researchers do not know enough about werewolf syndrome to cure it. Sufferers must treat the physical symptoms through methods like electrolysis and laser hair removal. These treatments may not completely eliminate the excessive hair, but they can greatly reduce it.

People with werewolf syndrome don’t exhibit wolf-like habits like howling at the moon and baring their fangs. They simply have a rare skin condition that usually presents itself at birth. Fortunately, most people have nothing to worry about since CHL does not happen very often. You can still watch your favorite werewolf movie and regard it as a tall tale steeped in legend.

This article first appeared on AskDrManny.com.