CASE REPORT
The patient is a 32-year-old woman (gravida 2, para 2) who presented with approximately a 3-year history of a recurrent eruption on her face and left arm. The eruption occurred cyclically, beginning 3 to 4 days prior to the onset of her menses and slowly resolved 1-2 days into the menstrual period. Her past medical history was significant for allergies to sulfur based antibiotics and codeine, both of which produced pruritus and urticaria. She had multiple seasonal allergies and a history of allergic sinusitis. She also had undergone elective bilateral mastectomies approximately a year prior to her eventual diagnosis, for multiple bilateral Phyllodes tumors and then delayed reconstruction with bilateral breast implants. She had suffered from multiple fibroadenomas of both breasts since adolescence, requiring multiple biopsies and excisions. She reported that her menses were regular without history of prior oral contraceptive pill (OCP) use nor hormonal therapy to achieve her two pregnancies. Her pregnancies were uneventful and full term vaginal deliveries. She was married, did not smoke nor use illicit drugs, and worked full time as a registered nurse in the operating room of a local university hospital.On physical examination, the patient had a subtle, oval plaque measuring about 5 cm on her left shoulder with erythema and hyperpigmentation without any scale or crust noted (Figure 1). In addition, more troubling to the patient was the symmetric edema around both eyes with hyperpigmentation, mild erythema (Figure 1) and severe pruritus, poorly responsive to hydrocortisone 2.5% ointment, tacrolimus 0.1% ointment, fexofenadine, and loratadine. She had previously been evaluated by an allergist. The allergist performed routine patch testing, which was negative, and then attempted to control her cyclical eruptions with short courses of oral prednisone, which provided only temporary relief.A punch biopsy was performed of the lesion on the left shoulder during the acute outbreak and it revealed an interface dermatitis with postinflammatory pigmentary alteration. After careful review of this case with the dermatopathologist (Figure 2), the diagnosis of APD was a very strong consideration.The patient was referred to another dermatologist for further evaluation and work up. Confirmation of APD in this patient was imperative, as the patient’s gynecologist was reluctant to prescribe OCPs to this patient, due to her past medical history of bilateral Phyllodes tumors. The dermatologist performed an intradermal skin test using 0.1 mL of 50 mg/mL progesterone in sesame oil. The patient returned in 24 hours with an urticarial plaque at the site of the test injection on her left arm (Figure 3). The control site on the right arm, which was injected with 0.1mL of sesame oil, was non-reactive. A punch biopsy of the dermal plaque revealed a sparse perivascular and interstitial infiltrate of lymphoid cells, neutrophils, and eosinophils; urticaria consistent with the clinical impression of autoimmune progesterone dermatitis (Figure 4).The patient was started on Norethindrone acetate/ethinyl estradiol (Loestrin)10 mcg daily and soon after noted that the cyclical skin eruptions were less intense and shorter in duration. By the third month of
