A 25-year-old woman comes to the office due to excessive facial hair growth that has worsened over the past several years. The patient is very concerned and says it makes her feel self-conscious in public. She has tried several cosmetic measures, including laser removal and waxing, but the results have been unsatisfactory. Her past medical history is insignificant, and she takes no medications. The patient's last menstrual period was 6 weeks ago, but she regularly has long cycles and otherwise feels well. She is sexually active with her boyfriend and uses condoms for contraception. Examination shows moderate obesity with mild hirsutism on the face and chest. The patient is initiated on a combination oral contraceptive. Which of the following describes the primary mechanism by which this agent reduces hirsutism?

Question

A 25-year-old woman comes to the office due to excessive facial hair growth that has worsened over the past several years.  The patient is very concerned and says it makes her feel self-conscious in public.  She has tried several cosmetic measures, including laser removal and waxing, but the results have been unsatisfactory.  Her past medical history is insignificant, and she takes no medications.  The patient's last menstrual period was 6 weeks ago, but she regularly has long cycles and otherwise feels well.  She is sexually active with her boyfriend and uses condoms for contraception.  Examination shows moderate obesity with mild hirsutism on the face and chest.  The patient is initiated on a combination oral contraceptive.  Which of the following describes the primary mechanism by which this agent reduces hirsutism?

Quizplus · Accepted Answer

11ec160b_3ac9_123c_9249_77a86f31a764_MD0001_00 Excessive male-pattern hair growth in a woman is called hirsutism. Hirsutism can be due to increased androgen production (eg, polycystic ovary syndrome, Cushing syndrome, ovarian and adrenal tumors), increased local conversion of testosterone to dihydrotestosterone (DHT), or higher sensitivity of hair follicles to DHT (eg, idiopathic hirsutism). With excessive androgen exposure, soft, non-pigmented villous hair changes to coarse pigmented terminal hair in androgen-dependent areas of the body (eg, face, chest, back). Virilization occurs with very high androgen levels and is characterized by clitoromegaly, increased muscularity, and voice deepening in addition to hirsutism. The most common cause of hirsutism is polycystic ovary syndrome (PCOS), which is often associated with elevated androgen levels. Combination oral contraceptive pills (OCPs) are usually the first choice for treating hirsutism in PCOS. OCPs work by suppressing LH secretion from the pituitary, thereby decreasing ovarian androgen production. They also increase sex hormone-binding globulin synthesis by the liver, decreasing free testosterone levels. (Choice A) Ornithine decarboxylase is involved in DNA stabilization and repair. Inhibition leads to decreased cell growth and increased apoptosis. Eflornithine is a topical ornithine decarboxylase inhibitor used to decrease the rate of facial hair growth. (Choice C) Patients with PCOS who develop diabetes mellitus are usually treated with metformin, which increases insulin sensitivity. Metformin can also help normalize menses but would not improve hirsutism. (Choices D and E) Testosterone receptor antagonists (eg, spironolactone) are effective in suppressing androgen-dependent hair growth. 5-α-reductase inhibitors (eg, finasteride) decrease peripheral conversion of testosterone to DHT but are less effective than testosterone receptor antagonists in treating hirsutism. Both are strongly teratogenic. Educational objective: Male-pattern hair growth in a woman is called hirsutism; the most common cause is polycystic ovary syndrome. Combination oral contraceptive pills can treat hirsutism by suppressing pituitary LH secretion and subsequently decreasing ovarian androgen production. __________ References: Evaluation and treatment of hirsutism in premenopausal women: an endocrine society clinical practice guideline. (http://www.ncbi.nlm.nih.gov/pubmed/18252793) Hirsutism in women. (http://www.ncbi.nlm.nih.gov/pubmed/22335316)

A 25-Year-Old Woman Comes to the Office Due to Excessive