Hypertrichosis is a very sad and misunderstood disorder of excessive, unwanted body hair. Unfortunately, some of the individuals with severe hypertrichosis have been displayed in carnival sideshows with names like “dog-boy” or the “bearded lady.”
In this disorder, nearly all of the skin on the body except the palms of the hands and the soles of the feet are covered with hairs. The density of the hairs, the thickness, color, speed of hair growth and qualities such as kinkiness, vary from one part of the body to another and from one person to another. The disease can be generalized, affecting most of the body; or localized, affecting an area of skin or just small patches.
Hypertrichosis may be congenital (present at birth) or acquired (arises later in life).
Congenital Hypertrichosis Lanuginosa
This is a very rare syndrome with only about 50 cases verified in the world since the Middle Ages. The condition consists of excessive hair growth on the infant at birth. Normally, babies in utero are covered in lanugo hair which is unpigmented, very soft, silky, fine hair that covers the fetus and is usually shed around eight months gestation. It is replaced then with fine vellus (the fine hair present on the body before puberty) hair and scalp hair in preparation for birth. In congenital hypertrichosis, the lanugo hair continues to grow and this long fine hair persists through life.
Congenital Hypertrichosis Terminalis
This condition is a variant of congenital hypertrichosis except in this condition, the whole body is involved with excessive, fully pigmented hair growth. This condition is usually accompanied by gingival hyperplasia (teeth defects). Other abnormalities are associated with congenital hypertrichosis and seem to be mostly associated with the eyes, shape of face and nose and some nerve palsy.
The cause of hypertrichosis is unknown. Congenital hypertrichosis is thought to be a genetic disorder that is inherited or occurs as a spontaneous mutation.
In 1648, an entire family with hypertrichosis was documented. A man, his two daughters, a son, and a grandchild were affected.
In 1984, a family from Mexico was reported to have 24 members with hypertrichosis. Affected persons were found in 5 generations. The father passed the mutant gene to all four of his daughters but none of his nine sons. The world average is one individual affected with hypertrichosis out of 340 million.
Most cases of hypertrichosis are genetic, but a small number of unusual systemic disorders can cause increase in vellus hair. In addition, drugs such as diazoxide, diphenylhydantoin and minoxidil can cause unusual hair growth and toxins such as mercury can induce generalized hair growth as well. Sometimes hair growth is cancer related. Untreated malnutrition as seen in anorexia nervosa also causes unusual hair growth.
There is no cure for hypertrichosis, The only treatment for hypertrichosis is cosmetic. Treatments range from bleaching the hair to temporary removal by waxing or permanent removal by electrolysis or laser destruction of hair follicles. Fortunately, this is an extremely rare disorder.
