Pregabalin-induced delayed cutaneous hypersensitivity reaction occurring after 40 days of use: a case report

Pregabalin is the first-line treatment for neuropathic pain. Cases of cutaneous hypersensitivity reactions caused by pregabalin generally occur within 2 weeks of initiating medication. We report a rare case of a delayed cutaneous hypersensitivity reaction caused by pregabalin, which was confirmed by a drug provocation test. A 72-year-old man with severe herpes zoster neuralgia developed maculopapular drug eruption covering 80% to 90% of his total body surface area after 40 days of combined multidrug analgesia. A drug provocation test for pregabalin was positive. The time interval between initiating medication and the onset of the patient's rash was the longest and he also had the largest area of skin affected compared with patients with a similar condition in previous related reports. Remaining vigilant for possible adverse cutaneous hypersensitivity reactions during treatment is important because of the long-term course of pregabalin treatment for neuropathic pain.