Hirsutism and virilism in women.
Hirsutism in women may be defined as excessive thick (terminal) hair growth in facial and body regions. It is one of the early manifestations of virilization that correlate closely with elevated testosterone production. Testosterone production rates in normal women average 0.2 mg/day, with 25% secreted by the ovaries, 25% by the adrenals, and 50% arising from the peripheral metabolism of prehormones, notably androstenedione. Increased testosterone from adrenal and/or ovarian sources induces 5 alpha-reductase activity within the susceptible hair follicle. This results in the local production of dihydrotestosterone, the potent androgen that is likely responsible for the growth and stimulation of the hair follicle that leads to hirsutism. Activation of the hair follicle by androgens provides a secondary pathway for testosterone metabolism, unfortunately at the expense of undesirable hair growth. Although virilization in women may be caused by exogenous androgens, it occurs primarily from diseases of the adrenals or ovaries. Androgen-producing tumors of the adrenals cause virilization in association with excessive production of a wide variety of C19 androgens. In contrast, ovarian tumors tend to secrete a narrower range of androgens and their presence may be more occult. The most common causes of hirsutism in women arise from nontumorous states, chiefly ovarian in origin. The androgenized ovary syndrome represents a spectrum of abnormalities ranging from idiopathic hirsutism to the polycystic ovary syndrome to ovarian hyperthecosis. These states are associated with mild to severe abnormalities of androgen production and concomitant mild to severe abnormalities of ovarian histology. The pathogenesis of these abnormalities is still speculative, but appears to be related to increased pulsatile and tonic secretion of LH with ovarian hyperstimulation. Of the various laboratory tests to evaluate hirsutism, simple measurements of plasma testosterone, free testosterone, and most recently androstanediol glucuronide seem to provide the best chemical evidence of androgen abnormalities. Treatment of hirsutism/virilism in women is difficult and frequently unsatisfactory. At present, treatment schemes include local methods, suppression of androgens via glucocorticoids or oral contraceptives, and antiandrogens.