Hypertrichosis, excessive growth of hair, is caused by several factors. Hypertrichosis may be congenital, being present at birth. It may also be acquired later in the life.
The excess hair growth may be generalized, affecting the whole of the body or localized to form well defined patches. Hypertrichosis may involve all the three types of hairs; vellus hair, lanugo hair or terminal hair. The various types of excess hair growth and their causes are discussed below.
Common causes of hypertrichosisCommon health conditions like hormonal, endocrine disturbances, systemic illness and certain diseases can induce excessive growth of hair.
Some of the common factors inducing acquired hypertrichosis are:
- anorexia nervosa,
- porphyria cutanea tarda,
- pituitary abnormalities,
- hypothalamic abnormalities,
- Becker’s nevus,
- head injury,
- friction and
|Functions of the hypodermis|
|Permanent skin lightening|
- Congenital erythropoietic porphyria (Gunther disease) is a rare, autosomal recessive metabolic disorder affecting heme, caused by deficiency of the enzyme uroporphyrinogen cosynthetase. Exposure to long-wave ultraviolet light causes vesiculobullous lesions, hyperpigmentation and excessive growth of hair.
- CH lanuginosa is considered to be due to autosomal dominant mutation on chromosome 8q.
- Generalized CH is considered to be due to autosomal dominant mutation on chromosome x24-q27.1.
- CH generalized terminalis is due to a mutation in MAP2K6 on chromosome 17.
- Localized CH may be associated with nevus, especially melanocytic naevus.
- Abnormal localized lumbosacral hypertrichosis or faun-tail nevus is usually a marker for spinal dysraphism like spina bifida occulta or diastematomyelia.
Drug induced hypertrichosisMany medications have been found to induce excessive hair growth. Some of the medications and chemicals inducing excessive hair growth are listed below:
- Topical minoxidil,
- Acetazolamide and
Treatment optionsThere is no treatment for congenital forms of excessive hair growth. Acquired forms resolve when the factors responsible excessive hair growth are removed or discontinued. Hair removal methods like shaving, waxing, laser hair removal and electrolysis are the treatment options available for congenital excessive hair growth.
1.Trüeb RM. Causes and management of hypertrichosis. Am J Clin Dermatol. 2002;3(9):617-27.
2.Goel N, Rajaram S, Gupta B, Gupta K. Familial congenital generalized hypertrichosis. Indian J Dermatol Venereol Leprol 2013;79:849.