A case of fixed drug eruption aggravated by redosage

Abstract

A 30-year-old male patient developed erythema on his lips, fingers and penis shaft after taking over-the-counter analgesic. No ingredients of the medicine were positive for patch test reactions even on the erupted lesions. However, an oral challenge test with allyl-isopropyl acetylurea was positive on the erupted lesions. We diagnosed this case to be a fixed drug eruption due to allyl-isopropyl acetylurea. TWO years later, he took a medicine containing allyl-isopropyl acetylurea that had been mistakenly prescribed by his family doctor. This time he presented with bullous eruptions in addition to erythema and the eruptions were even observed on his intraoral mucosa. He was treated with steroids for 2 weeks and the eruptions were successfully cured.