[A severe epicutaneous test reaction to the bufexamac in a hemorrhoidal therapeutic preparation].

A 49-year-old woman presented with acute perianal vesicular/bullous contact dermatitis. Other areas were over the trunk, face, neck and wrists. She reported occasional application of an ointment (Mastu S) to treat her hemorrhoids. Patch tests (basic series, anal block, own ointment, local anesthetic, cosmetics) provoked strong vesicular and bullous reactions of persisting crescendo type, spreading far beyond the site of application, to Bufexamac, to a derivative of hydroxxamine acid, and to local applied ointment with mild or moderate antiinflammatory action. A week after the patch tests there was a flare-up of the previous foci of dermatitis. These reactions subsided two days later after intravenous injection of prednisolone. The skin lesions healed after rapid reduction of the systemic treatment and local application of corticosteroids, bathing with tanning substances and basic preparations. While Bufexamac is not absorbed when applied rectally, perianal contamination may not be avoidable on intra-anal application and can produce sensitization.