Hirsutism affects androgen-dependent areas of a woman’s body and only involves terminal hair – the thick, pigmented hair found on the scalp, beard, armpit and pubic areas.
Although the terms hirsutism and hypertrichosis are often used interchangeably, hypertrichosis involves excess hair growth in areas of the body that are not androgen dependent. Notably, hypertrichosis involves excess lanugo and vellus hair, which are fine, downy and non-pigmented and resemble peach fuzz.
Most forms of hirsutism are idiopathic and occur in women with normal levels of male hormones who do not have menstrual abnormalities — especially after menopause and among those with dark hair. Idiopathic hirsutism is believed to be caused by hair follicles that are overly sensitive to male hormones.
Hirsutism may also be a manifestation of a more serious underlying malignancy, such as ovarian or adrenal neoplasms. Any condition that increases blood levels of testosterone, male sex hormone or androgen can cause hirsutism including: polycystic ovary syndrome, congenital adrenal hyperplasia, and androgen-producing tumors of the ovary or adrenal gland.
Certain medications, especially those that affect androgen levels, can induce hirsutism. These include dehydroepiandrosterone sulfate (DHEA-S), testosterone, danazol, and anabolic steroids. Other drugs associated with hirsutism include phenytoin, minoxidil, diazoxide, cyclosporine, streptomycin, psoralen, penicillamine, high-dose corticosteroids, metyrapone, phenothiazines, acetazolamide, and hexachlorobenzene.
Hirsutism refers to excess hair growth in women that occurs in areas of the body normally associated with post-pubescent males – such as the moustache, beard, chest and inner thigh. The disorder affects about one in 20 women between the ages of 18 and 45 years.