Allergic contact dermatitis from transdermal buprenorphine.

BACKGROUND Buprenorphine is a low-molecular-weight, lipophilic, opioid analgesic. The transdermal delivery system (TDS) containing it has skin irritation potential, but at least two cases of contact allergy to the active principal have been described previously. OBJECTIVE To confirm allergic contact dermatitis from transdermal buprenorphine (TDB) in five older patients suffering from chronic pain and who developed persistent, pruritic erythematous plaques at the contact sites, with two of them also presenting with a generalized skin eruption. METHODS Besides the baseline patch test series, all five patients were tested with the TDB, four of whom were also tested with the placebo transdermal delivery system as provided by the manufacturer; one patient was also tested with other preparations containing buprenorphine. RESULTS All reacted to the TDB containing the active principal, the placebo being negative in the four patients tested. The patient tested with the other buprenorphine preparations did react positively to them as well. Tests with TDB in 28 healthy controls were negative. CONCLUSION We report five cases of delayed hypersensitivity reactions to a TDS containing buprenorphine. Such adverse reactions might be under-reported. A fentanyl-containing TDS is a good alternative in these cases.