Nimesulide-Induced Fixed Drug Eruption Followed by Etoricoxib-Induced Fixed Drug Eruption: An Unusual Case Report and Review of the Literature.

Fixed drug eruption (FDE) is a well-recognized, non-immediate, drug hypersensitivity reaction, often attributed to the use of various medications, most commonly non-steroidal anti-inflammatory drugs (NSAIDs) and antibiotics. Cross-reactivity between related NSAIDs in FDE has been reported, but among chemically unrelated NSAIDs, is rare. Herein, we present a rare well-documented case where a patient initially displayed tolerance to etoricoxib after experiencing a nimesulide-induced FDE. Subsequently, the patient developed an etoricoxib-induced FDE, accompanied by the development of bullous lesions. This case report and the literature review on comparable FDE occurrences shed light on the intricate nature of FDEs, suggesting the possibility of cross-reactivity between chemically related and unrelated NSAIDs or the emergence of new drug-specific T cells without cross-reactivity after multiple exposures to a drug in a susceptible patient. Our case underscores the importance of increased awareness and vigilance among both physicians and patients in the realm of personalized medicine. Further research is needed to unravel the intricate mechanisms behind these drug eruptions, improve diagnostic approaches, and enhance patient care.