Figure 3: Sex difference in hidradenitis suppurativa. In hidradenitis suppurativa, men are prone to have lesions on the buttocks, while women are common to have lesions on the regions of axillae, groins, and breasts. Men with hidradenitis suppurativa usually have an acne history suggesting that androgen may play a role in the pathogenesis of hidradenitis suppurativa and acne. The expression of androgen receptors in the sinus tracts of hidradenitis suppurativa is higher in men. Women with hidradenitis suppurativa have premenstrual and postpartum flares. The possible hormones associated with the flare-up of premenstrual and postpartum are progesterone and prolactin, respectively. After menopause, the level of progesterone is decreased, and the symptoms of hidradenitis suppurativa are usually improving. The figure was drawn by using the commercial web-based software purchased from BioRender.com.