Resolution of autoimmune progesterone dermatitis after treatment with oral contraceptives.

OCP: oral contraceptive pill CASE REPORT A 20-year-old woman presented with a 6-year history of recurrent erythematous papules and plaques on the trunk. The eruption recurred cyclically, beginning 5 days before menses and resolving 1 to 2 days after the menstrual period. The lesions were asymptomatic, and there were no associated systemic symptoms. She had not previously sought treatment. Her medical history was unremarkable, and she was not taking any medications. Examination found widespread erythematous and edematous papules and nonscaly plaques, on the chest, back, and lower neck (Fig 1). Lesions were uniform in color, ranging in size from 3mm to 4 cm in diameter. A biopsy specimen was taken for histopathologic evaluation (Fig 2). Results of a punch biopsy of the skin showed dermal perivascular lymphohistiocytic inflammation, with rare eosinophils. An intradermal progesterone test read at 20 minutes was positive (progesterone, 50 mg/mL at a dilution of 1:10 in aqueous solution elicited a 10-mm wheal vs a 4-mm wheal for the glycerine control). The patient was started on levonorgestrel/ ethinyl estradiol, 0.1 mg to 20 g daily. There was a marked reduction in the number of lesions during her next menstrual period. By the third menstrual cycle, after beginning oral contraceptive pills (OCPs), no lesions appeared perimenstrually. The patient remained clear for another 4 months while taking Levonorgestrel/Ethinyl Estradiol 0.1 mg to 20 g. She then discontinued treatment because of the loss of health insurance. Despite discontinuing OCPs, lesions have not returned in the 8 months since the medication was stopped.