Cerci, PamirKendirlinan, ReşatBüyüköztürk, SunaGelincik, AslıÜnal, DeryaDemir, SemraErkekol, Ferda ÖnerKarakaya, GülDursun, Adile BernaÇelikel, SerhatEdiger, DaneAbadoglu, ÖznurBavbek, Sevim2024-11-142024-11-142023-01-010301-0546https://doi.org/10.15586/aei.v51i5.946https://www.all-imm.com/index.php/aei/article/view/946https://hdl.handle.net/11452/47880Background: Hypersensitivity reactions (HSRs) to nonsteroidal anti-inflammatory drugs (NSAIDs) are a significant clinical issue. Several classifications have been proposed to categorize these reactions, including the current European Academy of Allergy and Clinical Immunology/ European Network for Drug Allergy (EAACI/ENDA) classification. This study aimed to evaluate the applicability of this classification in a real-world clinical setting.Methods: We conducted a national multicenter study involving patients from nine hospitals in four major urban centers in Turkey. All patients had a suggestive clinical history of hypersensitivity reactions to NSAIDs. Researchers collected data using a structured form and classified reactions based on the EAACI/ENDA classification. Oral provocation tests with several NSAIDs were performed using a single-blind challenge per EAACI/ENDA guidelines.Results: Our retrospective study included 966 adult patients with a history of hypersensitivity to NSAIDs. The most common triggers were Acetylsalicylic Acid (ASA), paracetamol, and metamizole. The most prevalent acute NSAID hypersensitivity group was NSAID-induced urticaria/ angioedema (NIUA) (34.3%). However, 17.3% of patients did not fit neatly into the current EAACI/ENDA classification. Notably, patients with underlying asthma or allergic rhinoconjunctivitis exhibited unusual reactions, such as urticaria and/or angioedema induced by multiple chemical groups of NSAIDs, blended mixed reactions, and isolated periorbital angioedema in response to multiple chemical groups of NSAIDs.Conclusions: While the EAACI/ENDA classification system stratifies NSAID-induced hypersensitivity reactions into five distinct endotypes or phenotypes, it may not fully capture the diversity of these reactions. Our findings suggest a need for further research to refine this classification system and better accommodate patients with atypical presentations.eninfo:eu-repo/semantics/openAccessManagementDiagnosisAspirinNsaidsAdverse drug reactionsClassificationHypersensitivityNsaidsPhenotypingScience & technologyLife sciences & biomedicineAllergyImmunologyArticle001108912900008849251510.15586/aei.v51i5.9461578-1267