RESUMO
BACKGROUND: Idiopathic anaphylaxis (IA) is an unresolved concern. Hidden allergens may be relevant in IA and in non-steroidal anti-inflammatory drug hypersensitivity (NSAID-HS). OBJECTIVE: To identify hidden elicitors for IA and NSAID-HS by a skin prick test (SPT; 13 allergens) and allergen-specific IgE (sIgE; 12 allergens) panel and to determine the value of each tested allergen. METHODS: We retrospectively included all patients from 2018 to 2021 referred with a suspicion of IA or NSAID-HS by history in whom SPT and/or sIgE to allergens of the IA panel were performed. Patient characteristics from patients' records included comorbidities, history and symptoms of anaphylaxis, serum baseline tryptase level (sBT), total IgE level, SPT, sIgE, challenge results and final diagnoses. RESULTS: 134 patients (77 female; mean age 39.7±14.6 years) were included. Median sBT and total IgE levels were 4.23 µg/l and 133.5 kU/L, respectively. Allergological workup with the IA panel resulted in positive SPT and sIgE in 61 (47%) and 66 (60%) patients, respectively. In those, confirmation or exclusion of allergy, mostly by challenge, led to a definitive diagnosis in 61/134 patients (46%). SPT was most frequently positive to gluten (22.4%) and sIgE to ω5-gliadin (21.6%), which correlated with the history (r=.310 p<0.001 and r=.407 p<0.001, respectively). In 28/134 (21%) of patients with initially suspected IA or NSAID-HS, challenges confirmed occult food allergy with wheat allergy dependent on augmentation factors (WANDA) being the most frequent cause of anaphylaxis (19%). CONCLUSIONS: WANDA should be considered in all patients with anaphylaxis of unknown cause or after NSAID intake.
