A 47-year-old Caucasian woman had a pruriginous dermatitis involving her axillary, infra-mammary and inguinal flexures, and the lateral aspects of her trunk. Confluent erythematous patches without epidermal detachment were observed, sparing the extremities and mucous membranes (Fig. 1). There were no systemic symptoms. A week before the onset of dermatitis, she was started on aminocaproic acid treatment (9 g/day) for excessive vaginal bleeding due to uterine myomatosis. The drug was promptly withdrawn when the cutaneous lesions appeared. The patient was not on any other systemic or topical formulations. Complete remission of the skin lesions was achieved with oral antihistamines, topical corticosteroids, and emollients. Patch tests were performed 6 weeks after resolution of the lesions. Finn® chambers on Scanpor® tape were used and readings were made at D2 and D3 in accordance with the International Contact Dermatitis Research Group (ICDRG) criteria. Aminocaproic acid (30% pet. Epsicaprom®, Bial®, Portugal) showed a strongly positive reaction (+++). Aminocaproic acid diluted to a 1% aqueous solution (Bial®, Portugal) elicited a reaction (+) at D2 and D3, but both 5% aqueous and 10% aqueous aminocaproic acid elicited strong positive reactions at D3 (++ and +++, respectively; Fig. 2). The Portuguese baseline series was also applied but no further positive reactions were seen. Epsicaprom® (30% pet.) patch testing elicited no reactions in 10 healthy controls.