A transdermal patch of trouble

A 79-year-old man, with a history of penicillin allergy, hypertension, diabetes mellitus, and multiple vertebral fractures secondary to severe osteoporosis, developed a pruritic, erythematous reaction limited to the site of application of transdermal buprenorphine.

He had been applying transdermal buprenorphine patches for several weeks for chronic back pain before the lesions developed. After withdrawal of the transdermal buprenorphine and the use of topical high-potency corticosteroids, the lesions resolved. Skin patch tests with transdermal buprenorphine showed a papular erythematous reaction, suggesting a delayed hypersensitivity reaction.