Autoimmune progesterone dermatitis diagnosed by intravaginal progesterone provocation in a hysterectomised woman

We report the case of a 39-year-old Hungarian woman who cyclically experienced painful, erythematous, patchy skin lesions on her face and chest. Because of her irregular menses and hysterectomy performed later on to manage endometriosis, it was difficult to link her symptoms to the menstrual cycle. But on the basis of the cyclic nature of the rash and the previous negative results - acne vulgaris, psoriasis, atopic dermatitis, lichen planus, systemic lupus erythematosus and infections were ruled out - autoimmune progesterone dermatitis was suspected. As progesterone is not available in aqueous solution for intradermal allergen test in Hungary, we performed progesterone provocation vaginally. The patient developed the usual skin lesions to vaginal progesterone exposure, which confirmed the diagnosis. The patient became symptom free to gonadotropine-analogue treatment and remained so even after the cessation of the therapy after 6 months. To our knowledge, this is the first case in the medical literature, in which autoimmune progesterone dermatitis was proved by vaginal progesterone provocation.