Hypertrichosis

Hypertrichosis
Specialty	Dermatology

Hypertrichosis, congenital generalized Hypertrichosis or werewolf syndrome is a medical term referring to a condition of excessive body hair. Werewolf syndrome comes from the characteristics of a mythological werewolf of which the person is completely covered in hair or fur. It can be generalized, symmetrically affecting most of the torso and limbs, or localized, affecting an area of skin. It may be mild or severe. In most cases, the term is used to refer to an above-average amount of normal body hair that is unwanted and is an aspect of human variability.

In medical practice, once generalized hypertrichosis has been distinguished from hirsutism, it is most often considered a variation of normal, primarily resulting from genetic factors.

Although the statistic has been cited that this only occurs for 1 out of 10 billion people, 19 people alive today have hypertrichosis, out of ~6.5 billion people in the world, makes for an average of 1 in 340 million.

Body hair

Nearly all the skin of the human body except palms of hands and soles of feet is covered with hair. The density of the hair (in hair follicles per square centimeter) thickness of the hair, color of the hair, speed of hair growth, and qualities such as curliness, vary from one part of the body to another, and from one person to another. All of these features have strong genetic determinants, as demonstrated by the heritability of these qualities.

Doctors generally distinguish scalp hair, vellus hair, and androgenic (terminal) hair. Scalp hair is the hair on the head. Its absence is termed "baldness." Vellus hair is the hair on the rest of the body which has not been stimulated and transformed by sex hormones. Androgenic hair is the hair that greatly increases in heaviness and rate of growth with puberty.

Vellus hair

Even children are covered with fine vellus hair, varying in density, length, and heaviness, but usually white due to a lack of pigment.

A slight genetic variation or variation in hormone signalling can turn this vellus hair into full thickness hair. Pigmented thick hair may grow from a scar, possibly because in the process of growing a scar, the vellus hair follice is triggered into to growing as a thicker pigmented hair follicle.

Also, thick, pigmented hair is noted to grow on the skin near the site of a spinal injury. It is the ordinarily vellus hair follicle responding to a signal even though there is no scar, callous, or other change to the skin.

Duck down

With yet another minor genetic variation, a single hair follicle may start producing a bunch of hairs, which remain in a bundle at the base, but split apart if it grows long enough, and this resembles duck down. This is most common in male facial hair.

Androgenic hair

Annie Jones, who suffered from hirsutism.

The hair follicles on much of the body respond to androgens (primarily testosterone and its derivatives). Generally, the rate of hair growth increases and the heaviness of the hairs increases in direct proportion to the androgen levels. However, different areas respond with different sensitivities. As puberty progresses, the sequence of appearance of sexual (androgenic) hair reflects the gradations of androgen sensitivity. The pubic area is most sensitive, and heavier hair usually grows there first in response to androgens. The following regions also respond to androgens, in order of decreasing sensitivity: axillary and perianal areas, sideburns, above the upper lip, periareolar areas, chin and beard areas, arms and legs, chest, shoulders, buttocks, back, and abdomen.

It is the hair in these areas that appears earlier or grows to excess in disorders of excess androgen (e.g., precocious puberty, late-onset congenital adrenal hyperplasia, and polycystic ovary syndrome).

Vellus hair and hypertrichosis

When the unwanted or excessive hair occurs in other places, and especially in other sequences of appearance, it is rarely due to a disorder of androgen excess. For example, it is not unusual for a young girl to be taken to a pediatric endocrinologist because her mother is distressed by the heaviness of the girl's arm and leg hair, but this condition is never due to a disorder of androgen excess if pubic hair has not appeared.

Most hypertrichosis is genetic, but a small number of unusual systemic disorders can sometimes increase vellus hair. Some drugs (e.g., diazoxide, diphenylhydantoin, and minoxidil) and toxins (e.g., mercury) can induce generalized hair growth as well. Unusual hypertrichosis can also be caused by untreated infection, or by malnutrition. For this reason, it is an occasional sign of anorexia nervosa.

Severe hypertrichosis

Severe hypertrichosis is quite rare, almost certainly due to unknown genetic defects, and can result in excessive or animal-like hair on both face and body. Some of these people have been displayed in carnival sideshows with names such as "dog-boy" or the "bearded lady." Fedor Jeftichew, Stephan Bibrowski and Annie Jones are well known examples.

Most of the people recently featured in the media with hypertrichosis are from the Aceves clan of Loreto, Zacatecas, Mexico, some of whom have emigrated to the United States. Many of them have worked for circuses. The brothers Victor Ramon "Danny" Ramos and Gabriel "Larry" Ramos have worked as acrobats. Their cousins, Jesus "Chuy" Aceves, and his sister, Lili, have worked in sideshows.

Localized hypertrichosis

In some cases an area of skin can react to repeated trauma or to some other asymmetric stimulus (such as wearing of a cast) with increased hair growth.

Treatment

In the vast majority of cases, hypertrichosis is a cosmetic problem. The treatments range from camouflage (e.g., bleaching with hydrogen peroxide), to temporary removal by waxing, or permanent removal by electrolysis or laser destruction of hair follicles.

Cultural references

• An episode of CSI, (first aired January 5 2006) featured the murder of a man with hypertrichosis. His sister had the same syndrome, though it affected her more severely.
• This condition was also used as the basis for the character of Tara in the film Wolf Girl.
• In the novels Black Notice, The Last Precinct, and Blowfly by Patricia Cornwell, the character Jean-Baptiste Chandonne suffers from congenital hypertrichosis.
• In the novel The Lion Woman by Erik Fosnes Hansen, the character Eva Arctander has congenital hypertrichosis lanuginosa.
• The film Human Nature features a woman, played by Patricia Arquette, who suffers from severe hypertrichosis.
• The film Fur : an imaginary portrait of Diane Arbus (2006) (starring Nichole Kidman as the title character) features an invented character called Lionel (played by Robert Downey Jr.) who has severe hypertrichosis. He typifies the kind of freakishness which inspired Arbus to make people living on the fringes of society the subjects of much of her photographic work.
• "Colonel Doctor" from the TV series "Scrubs" is believed to have Hypertrichosis which caused him to grow a beard at the age of nine.
• In a Suffolk school, it was discovered that 20% of the mass of a pupil there was due to his hair. Thomas Mitchell is soon to be put into an intensive treatment unit to cure his excessive hair growth.

See also

• Hirsutism
• Hair
• Facial hair
• Chest hair
• Abdominal hair
• Pubic hair