Tree Nut and Peanut Allergy in a Portuguese Pediatric Cohort- Clinical Characterization and Anaphylaxis PredictorsLeonor Esteves

Abstract

Background: Tree nuts and peanuts (TN/P) are frequent causes of anaphylaxis in children. Our aim was to characterize a Portuguese pediatric cohort with TN/P allergy and to assess skin tests (ST), specific IgE (sIgE) and molecular components (mcIgE), as well as sIgE/total IgE ratio's utility in anaphylaxis prediction. Methods:Retrospective study (2017-2021) of pediatric patients with TN/P allergy, grouped according to reaction severity (group 1-anaphylaxis vs group 2-milder reaction). ST mean papule diameter (MPD), sIgE (ImmunoCAP®), mcIgE (ISAC®) and sIgE/total IgE ratio were compared (SPSS®, p<0.05: statistically significant).Results: A total of 98 patients were included, 64% male. 88% had concomitant allergic disease and 40% had allergy family history. The more common culprit nuts were peanut (47%), walnut (31%) and hazelnut (13%). Index reaction symptoms were mostly cutaneous (46%), followed by anaphylaxis (36%). Chestnut and cashew sensitization were significantly associated with anaphylaxis (OR=5.023, p=0.002; OR=2.901, p=0.018). MPD was higher in G1 for almond, cashew, and pistachio (p<0.05). sIgE was not a good severity predictor for any TN/P, however, a significantly higher sIgE/total IgE ratio was found in G1 for walnut (p=0.023). McIgE was obtained in 49%: peanut Ara h2 and Ara h6 were more represented in G1 (2.8 vs 0 ISU-E, p=0.042; 1.3 vs 0 ISU-E, p=0.020). Conclusion:Peanut, hazelnut and walnut were the most frequent nuts involved in TN/P allergy. Anaphylaxis was the first manifestation in 36% of the patients, significantly more frequent in chestnut and cashew allergic children. The authors suggest that MPD should be valued not only for diagnosis, but also for anaphylaxis risk prediction in almond, cashew, and pistachio allergic patients. sIgE/total IgE ratio seems to be useful in anaphylaxis prediction.