Tree nut and peanut allergy in a Portuguese pediatric cohort -- clinical
characterization and anaphylaxis predictors
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.