USMLE Step 2 CK Lecture Notes 2019: Obstetrics/Gynecology (Kaplan Test Prep)

GYN TRIAD

Idiopathic  (Hair   Follicle)   ↑   5-α Reductase   Activity

Idiopathic: typically the onset has been gradual, frequently with a positive
family history. Menses and fertility are normal. This is the most common cause
of androgen excess in women.

Gradual-onset   hirsutism

Normal  exam

Normal  DHEAS,  testosterone,   17-OH   progesterone

Examination.    Physical    examination reveals hirsutism   without virilization.

Pelvic  examination is  normal.

Laboratory  tests.  Normal  levels  of  testosterone,   DHEAS,  and 17-OH

progesterone    are identified.

Management. Spironolactone, a   potassium-sparing   diuretic    whose

mechanism   of  action  as  an  antiandrogen    is  twofold:    it  is  an  androgen-receptor

blocker and it  also    suppresses  hair    follicle    5-α reductase   enzyme  conversion

of  androstenedione and testosterone    to  the more    potent  dihydrotestosterone.

Eflornithine    is  the first   topical drug    for the treatment   of  unwanted    facial  and

chin    hair.   It  blocks  ornithine   decarboxylase   (ODC),  which   slows   the growth

and differentiation of  the cells   within  the hair    follicles.