[Physiopathology of the so-called idiopathic hirsutism (author's transl)].

The so-called idiopathic hirsutism almost invariably involves hormonal disorders. Through secretion and peripheral conversion of precursors, there is an increase in androgens (mainly testosterone and androstenedione), often produced by both ovarian and adrenal glands, whilst a diminution of the binding protein leads to an increase in free testosterone. As in male puberty, this process activates a 5 alpha-reductase in the pilosebaceous glands located in areas normally reserved to male hairiness. The enzyme, in turn, transforms testosterone into dihydrotestosterone in situ, and the latter induces and maintains hair growth.