Hypertrichosis (also called Ambras syndrome) is an abnormal amount of hair growth over the body; extensive cases of hypertrichosis have informally been called werewolf syndrome, because the appearance is similar to the werewolf. The two distinct types of hypertrichosis are generalized hypertrichosis, which occurs over the entire body, and localized hypertrichosis, which is restricted to a certain area. Hypertrichosis can be either congenital (present at birth) or acquired later in life. The excess growth of hair occurs in areas of the skin with the exception of androgen-dependent hair of the pubic area, face, and axillary regions.
Two methods of classification are used for hypertrichosis. One divides them into either generalized versus localized hypertrichosis, while the other divides them into congenital versus acquired.
Congenital forms of hypertrichosis are caused by genetic mutations, and are extremely rare, unlike acquired forms. Congenital hypertrichosis is always present at birth.
Congenital hypertrichosis lanuginosa is noticeable at birth, with the infant completely covered in thin lanugo hair. In normal circumstances, lanugo hair is shed before birth and replaced by vellus hair; however, in a person with congenital hypertrichosis lanuginosa, the lanugo hair remains after birth. The palms of the hands, soles of the feet, and mucous membranes are not affected. As the person ages, the lanugo hair may thin, leaving only limited areas of hypertrichosis.
Acquired hypertrichosis appears after birth
The multiple causes include the side effects of drugs, associations with cancer, and possible links with eating disorders. Acquired forms can usually be reduced with various treatments.
Hypertrichosis is often mistakenly classified as hirsutism
The primary characteristic of all forms of hypertrichosis is excess hair. Hair in hypertrichosis is usually longer than expected and may consist of any hair type (lanugo, vellus, or terminal). Patterned forms of hypertrichosis cause hair growth in patterns. Generalized forms of hypertrichosis result in hair
Hypertrichosis is diagnosed clinically via the occurrence of hair in excess of what is expected for age, sex, and ethnicity in areas that are not androgen- sensitive. The excess can be in the form of excessive length or density and may consist of any hair type (lanugo, vellus, or terminal)
There is no cure for any congenital forms of hypertrichosis. The treatment for acquired hypertrichosis is based on attempting to address the underlying cause. Acquired forms of hypertrichosis have a variety of sources, and are usually treated by removing the factor causing hypertrichosis, e.g. a medication with undesired side-effects. All hypertrichosis, congenital or acquired, can be reduced through hair removal. Hair removal treatments are categorized into two principal subdivisions: temporary removal and permanent removal.
Temporary hair removal may last from several hours to several weeks, depending on the method used. These procedures are purely cosmetic. Depilation methods, such as trimming, shaving, and depilatories, remove hair to the level of the skin and produce results that last several hours to several days. Epilation methods, such as plucking, electrology, waxing, sugaring, threading, remove the entire hair from the root, the results lasting several days to several weeks. Permanent hair removal uses chemicals, energy of various types, or a combination to target the cells that cause hair growth.
Laser hair removal is an effective method of hair removal on hairs that have color. Laser cannot treat white hair. The Laser targets the melanin color in the lower 1/3 of the hair follicle, which is the target zone.
Medication to reduce production of hair is currently under testing. One medicinal option suppresses testosterone by increasing the sex hormone-binding globulin. Another controls the overproduction of hair through the regulation of a luteinizing hormone