Autoimmune progesterone dermatitis (APD) is a rare disorder characterized by periodic skin lesions that erupt during the luteal phase of the menstrual cycle. Clinical manifestations of APD is caused by an unusual allergy to progesterone and has a wide range of clinical manifestations from eczema and urticaria to angioedema and erythema multiforme. A 46-year-old woman described recurrent, round erythematous plaques on the lower lip, both forearms and buttocks. These skin eruptions waxed and waned for 10 months, reoccurring 3-4 days before menstruation. Based on her medical history and physical examination, APD was suspected and the progesterone challenge test showed positive results. After treatment with oral prednisolone (30 mg/day) before menstruation, the severity of eruptions decreased dramatically but recurrence did not cease completely
