Fixed drug eruption caused by mefenamic acid: a case series and diagnostic algorithms

Summary Background: Fixed drug eruption is a fairly common drug-induced hypersensitivity reaction of the skin and the mucous membranes, which is characterized by the re-occurrence of the lesion(s) exactly on the previously involved sites after repeated administration. The pathogenetic mechanisms of this site-specificity are not fully elucidated. Patients and Methods: We report on three cases of fixed drug eruption, including a non-pigmenting generalized bullous fixed drug eruption, caused by mefenamic acid in its pure form. Results and Conclusion: Provocation tests with the assumed causative drug represent the gold standard for establishing the diagnosis and for identifying the culprit. Advantages and pitfalls of topical and systemic provocation tests as diagnostic approaches are discussed.