Chapter 24 HIRSUTISM
General Discussion
The following discussion of hirsutism focuses on adolescent girls. For a discussion of hirsutism in infants or children, please see Chapter 35, Precocious Puberty.
Any patient who has either physical evidence of hirsutism or significant concern over excess hair growth should be evaluated. When evaluating hirsutism, it is important to determine whether hirsutism exists alone or whether virilization is also present. This distinction is important because virilization may reflect a serious underlying pathologic condition such as malignancy. Virilization manifests with a wide range of signs of androgen excess, such as acne, hirsutism, frontotemporal balding, amenorrhea, oligomenorrhea, deepening of the voice, and clitoromegaly.
The most common triggering factor for hirsutism is excess androgen production. Although androgens may come from an exogenous source, androgen excess is most commonly endogenous. The two primary sources of endogenous androgens are the adrenal glands and the ovaries. The most common cause of hyperandrogenism presenting in a teenage girl is polycystic ovary syndrome (PCOS). The differential diagnosis also includes late-onset congential adrenal hyperplasia, virilizing tumors, Cushing syndrome, hyperprolactinemia, acromegaly, medications, and abnormalities of androgen action or metabolism.
A common endocrine disorder, PCOS affects 3% to 10% of premenopausal women. It represents a group of disorders associated with increased androgen production from the ovaries, adrenal glands, or both. The clinical presentation typically includes one or several of the following features: hirsutism, obesity, oligomenorrhea, anovulation, and infertility. At the 1990 National Institutes of Health (NIH) consensus conference, experts attempted to identify the key features needed to diagnose PCOS, noting the following as definite criteria: hyperandrogenism, menstrual dysfunction, clinical evidence of hyperandrogenism, and the exclusion of congenital adrenal hyperplasia. Probable criteria included insulin resistance, perimenarchal onset, an elevated ratio of luteinizing hormone (LH) to follicle stimulating hormone (FSH), and polycystic ovaries by sonography.
Patients with PCOS must be differentiated from individuals with variants of nonclassic congenital adrenal hyperplasia (CAH). The most common form of CAH is late-onset 21-hydroxylase deficiency. The diagnosis of nonclassic CAH can be made definitively by the use of adrenocorticotropin hormone (ACTH)-stimulation testing or can be inferred by measurement of early morning 17-hydroxyprogesterone levels.
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