Generalized Bullous Fixed Drug Eruption Secondary to Levocetirizine: A Lesson Learned!

Fixed drug eruption (FDE) is a unique type of adverse drug eruption characterized by a well-defined erythematous to violaceous patch that recurs at the same site upon re-exposure to causative drugs and resolves with hyperpigmentation. This distinct drug reaction is a type IV hypersensitivity reaction that is mediated by memory CD8+ T cells that reside in the basal layer of the epidermis of resting FDE lesions. Generalized bullous FDE (GBFDE) is the most severe form of FDE, presenting with widespread blisters and erosions that can be misdiagnosed as epidermal necrolysis. There are only two reports of levocetirizine-induced GBFDE in the literature to date. We hereby present a case of a 65-year-old male with GBFDE due to levocetirizine, which was misattributed to a more commonly implicated drug, that is, acetaminophen.