ABSTRACT
Background: Tree nuts and peanuts (TN/P) are frequent causes of
anaphylaxis in children. Aim: 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
(anaphylaxis–G1 vs milder reaction–G2). ST mean papule diameter
(MPD), sIgE (ImmunoCAP®), mcIgE (ISAC®) and sIgE/total IgE ratio were
compared (SPSS®, p<0.05: statistically significant).
Results: 98 patients, 64% male, 88% concomitant allergic
disorder, 40% allergy family history. Major culprit nuts: peanut
(63%), hazelnut (59%) and walnut (53%). Index reaction manifestations
were mostly cutaneous (46%), followed by anaphylaxis (36%). Chestnut
and cashew sensitizations 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 value of
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. Anaphylaxis was the first manifestation in 36%, significantly
higher in chestnut and cashew allergic children. 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.