Hirsutism affects between 5 to 15 percent of adult women surveyed for the condition. The excessive growth of coarse hair in a male-like pattern can cause significant distress and have multiple negative consequences for patients. Hyperandrogenism usually causes hirsutism. A review by Azziz stresses the need for a systematic evaluation of the patient and use of combination therapy.

The first step in the evaluation of hirsutism is confirmation of excessive coarse (terminal) hairs in a male-like pattern, because many patients who complain of excessive hair growth do not have true hirsutism. Several scoring systems have been developed, but they must be adapted to the ethnic and cultural group to which each patient belongs, because body hair is regarded very differently by different cultures.

The second step involves the identification of the disorders (e.g., adrenal hyperplasia, diabetes mellitus, thyroid dysfunction, ovulatory conditions) that could contribute to the etiology or complicate the management of hirsutism. The most common causes of hirsutism are androgenic. Approximately 70 to 80 percent of women with androgen excess have hirsutism. The most common cause of androgen excess is polycystic ovary syndrome (PCOS). Rarer androgenic causes include the insulin-resistant acanthosis nigricans syndrome, some forms of adrenal hyperplasia, and ovarian or adrenal androgen-secreting tumors. Approximately 5 to 15 percent of hirsutism cases are idiopathic (i.e., an underlying cause cannot be identified). Some of these women are believed to have enzyme overactivity in the hair follicles, causing hirsutism in spite of normal circulating hormone levels.

Establishing the etiology of hirsutism depends on a thorough medical and menstrual history plus a physical examination, followed by laboratory and other diagnostic tests targeting the most probable cause for the individual patient. Appropriate tests may include thyroid function; basal 17-hydroxyprogesterone level during the follicular phase of menstruation to exclude nonclassic adrenal hyperplasia; blood glucose and insulin levels; and measures of circulating androgen levels (total and free testosterone and dehydroepiandrosterone sulfate).

Pharmacologic treatment is directed at the underlying cause of hirsutism, with special attention given to associated risk factors. More than one half of women with PCOS are at significant risk of insulin resistance and diabetes. Suppression of ovarian androgens usually is obtained through the use of combined oral contraceptives. Use of estrogens alone (1.25 mg of conjugated equine estrogens daily) in appropriate women has been recommended. Oral contraceptives may be combined with long-acting gonadotropin-releasing hormone (Gn-RH) analogs, such as Lupron Depot in a dosage of 3.75 mg per month, but this approach generally requires two to three cycles for effect. Insulin resistance may respond to weight loss or therapy with metformin or troglitazone, but the effect on hirsutism may be modest. The most effective treatments combine androgen suppression with peripheral androgen blockade. Androgen-receptor blockers include spironolactone, flutamide, finasteride, and cyproterone acetate. These drugs have teratogenic potential and require secure contraception.

In addition to medical treatments, most women with hirsutism seek local treatments to minimize the appearance of unwanted hair. Shaving does not increase hair growth. Depilating agents can cause chronic skin irritation. Mechanical hair removal by waxing or plucking is discouraged because of the risk of trauma, ingrown hairs, and folliculitis. Electrolysis and laser therapy can be successful but have unwanted side effects, such as blistering and pigmentation changes. Eflornithine hydrochloride 13.9 percent cream is approved by the U.S. Food and Drug Administration for treatment of unwanted facial hair. This agent slows and miniaturizes hair growth but appears to require continuous application. It has been associated with improvement in 60 percent of cases in initial studies and requires at least eight weeks of treatment for effectiveness.