Approach to the Patient: Hirsutism

Abstract Hirsutism affects approximately 10% of women globally, with significant economic and quality of life impact. Facial and body terminal hair growth in a male-like pattern is determined by a number of factors, including circulating androgens, and tissue androgen receptor, 5α-reductase, 3α- and 17β-hydroxysteroid dehydrogenase, and ornithine decarboxylase content. The presence of hirsutism is usually determined by the modified Ferriman Gallwey (mFG) visual scale, assessing the amount of terminal hair at nine body sites (upper lip, chin, chest, upper and lower back, upper and lower abdomen, upper arms and thighs). Specific diagnostic cut-offs vary somewhat by ethnicity, although hirsutism is usually defined by an mFG score of >4-6. Hirsutism is a sign of polycystic ovary syndrome in 80-90% of affected women, idiopathic hirsutism in 5-10%, and, depending on ethnicity, 21-hydroxylase deficient non-classic adrenal hyperplasia in 1-10%. Rarer causes include androgen-secreting neoplasms, iatrogenic/drug-induced, acromegaly, Cushing’s syndrome, syndromes of severe insulin resistance/lipodystrophy, ovarian hyperthecosis, and chronic skin irritation. The choice of treatment for hirsutism depends on the severity of symptoms, the patient's reproductive goals, and the underlying cause. Clinicians should not underestimate the degree of patient distress caused by hirsutism. Further, women who complain of excess unwanted hair growth should be evaluated for underlying causes, regardless of the degree to which hirsutism is observable on examination. Management options include medical therapies, such as combined oral contraceptive pills and anti-androgens, and mechanical methods of hair removal. The most effective therapeutic strategy will involve a combination of these modalities, with shared decision-making a key driver.