Allopurinol is one of the causative drugs that induce fixed drug eruption (FDE). The lymphocyte transformation test(LTT) is a safe and reliable diagnostic procedure for drug allergy, but is reported to be rarely positive in patients with FDE. In the current case, we performed an LTT and successfully confirmed allopurinol as the offending drug. This casereport suggests that an LTT should be an optional diagnostic tool for FDE or delayed reaction due to allopurinol.
- Fixed drug eruption
- Lymphocyte transformation test