Rare condition: Thai schoolgirl Nat Sasuphan is one of some thirty people worldwide living with the rare condition of hypertrichosis.

Credit: CORBIS/Barbara Walton

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MELBOURNE: According to unreliable sources from medieval Europe, in the light of the full moon, some men transform into howling, hairy, wolf-like creatures.

Is it surprising, then, that sufferers of hypertrichosis – literally 'too much hair' – have ended up being tagged with 'werewolf syndrome'?

In the late 1500s Ulisse Aldrovandi, an Italian naturalist and doctor, wrote about an Austrian family who had excessive body hair. Since that time, fewer than 50 cases have been recorded, so it is as rare as it is remarkable.

Medical oddity

There is no known predilection for ethnicity or gender, although it is thought that of the less than thirty people currently living with the condition, 19 are from one family living in Mexico and the USA.

Werewolf syndrome is associated with the generalised form of hypertrichosis – excessive hair of the face and body, sparing the palms and soles – that occurs at birth, and is thought to be caused by rare genetic mutations of two types. One is caused by an abnormality on chromosome 22 and the other is as yet unidentified.

Milder disorders that cause similar hair growth can develop as a side effect of medications such as phenytoin (an anticonvulsant used in the treatment of epilepsy), cyclosporine (an immunosuppressant), diazoxide (a muscle relaxant), and corticosteroids (often used in the treatment of arthritis).

Hypertrichosis is quite different, however, from hirsutism – a condition that results in male patterns of hair growth in women who produce too much of the male hormones, androgens.

The manifestation of hypertrichosis varies considerably, from mild to severe. Cosmetic management options include bleaching, shaving, depilatory creams, waxing, electrolysis and laser removal.

Popular culture

As with many medical oddities, the syndrome has frequently featured in popular culture in the form of books, films and television series. The first episode of a recent series of CSI: Crime Scene Investigation, opens with a man with hypertrichosis found shot dead in his apartment; with a silver bullet of course, because this – like the stake in the heart for vampires – is mythology's advice for dispatching werewolves.

The DeJesus family in Mexico has won the Guinness World Records dubious distinction of being the world's hairiest family. The two most famous family members are Danny and Larry Gomez, who from the ages of six and eight were trained to be acrobats.

They, like seven-year-old Nat Sasuphan in Thailand, have no additional symptoms associated with their hairiness. And it seems they are amazingly well adjusted to their unusual appearance and the reactions of other people.