Hirsutism is the presence of terminal (coarse) hairs in females in a male-like pattern, affecting between 5% and 15% of women, depending on definition.
Hirsutism has a significant negative impact on psychosocial development and is usually a sign of an underlying endocrine abnormality-namely,
androgen excess. The most common cause of
androgen excess is the
polycystic ovary syndrome (PCOS), with 21-hydroxylase-deficient nonclassic adrenal
hyperplasia, the
hyperandrogenic insulin-resistant acanthosis nigricans syndrome,
androgen-secreting
tumors, and androgenic
drug intake occurring less frequently. However, although 70-80% of patients with
androgen excess demonstrate
hirsutism, this sign may be less prevalent among women of Asian extraction. Conversely, not all hirsute patients have evidence of detectable
androgen excess, as 5-15% of these women have "idiopathic
hirsutism," with normal ovulatory function and
androgen levels. There is a strong familial predilection for
hirsutism, primarily because the underlying endocrine disorders (eg, PCOS) and the factors regulating the development of hair growth (eg,
androgen receptor activity, 5alpha-
reductase activity) have a strong genetic component. The diagnostic evaluation of the potentially hirsute patient first involves confirming the presence of
hirsutism and then excluding associated or etiological abnormalities and disorders (eg, ovulatory dysfunction, adrenal
hyperplasia, diabetes,
thyroid hormone abnormalities). Treatment should be undertaken using combination
therapy, to possibly include 1) hormonal suppression (
oral contraceptives, long-acting
gonadotropin-releasing hormone analogues, and
insulin sensitizers), 2) peripheral
androgen blockade (
spironolactone,
flutamide,
cyproterone acetate, or
finasteride), and 3) mechanical/cosmetic amelioration and destruction of the unwanted hairs (electrology and, potentially,
laser hair removal). The application of
eflornithine hydrochloride 13.9% topical cream may also be useful to ameliorate unwanted facial hair growth. Overall, although
hirsutism is a frequent and distressing abnormality often signaling an underlying endocrine disorder, a systematic approach to evaluation will uncover the etiology, and combination
therapy will provide satisfactory treatment for most patients.