What is autoimmune progesterone dermatitis?
Autoimmune progesterone dermatitis (APD) is a rare skin condition in women that recurs in a cyclical manner corresponding to their menstrual cycles. It is thought to be a response of the skin to the hormonal changes that happen just before menses. Characteristically, the skin eruptions occur during the luteal phase or the late pre-menstrual phase of the cycle. This is when the blood level of the sex-hormone progesterone rises. The skin rash happens as an autoimmune response to the body’s own progesterone, hence its name. Within a few days of menstruation when progesterone level falls, there is partial to complete resolution of the rash. It will recur during the next cycle. Some patients have had previous exposure to external progesterone in the form of oral contraceptive pills. This is thought to pre-sensitize patients to react against their own internal progesterone. However, not all patients with APD are exposed to previous hormone therapy. It has been postulated that these patients
