1- Immunoalergology Department, Hospital de Dona Estefânia, Centro Hospitalar Universitário de Lisboa Central, Portugal
2- Imunology Department, Hospital de São José, Centro Hospitalar Universitário de Lisboa Central, Portugal
3- CEDOC, Integrated Pathophysiological Mechanisms Research Group, Nova Medical School, Lisboa, Portugal
- Reunião Internacional, apresentação sob a forma de Póster, Allergy School on Food Allergy, Paris 2019
- Reunião nacional, apresentação sob a forma de Póster, 40ª Reunião Anual da SPAIC, 11 a 13 de Outubro de 2019, Palácio de Congressos de Albufeira
Objective: The aim of this study was to characterize the population with IgE-mediated food allergy (FA) to tree nuts and peanuts (TN/P).
Methods: Retrospective analysis of the clinical records of patients of an Allergology Department, who performed TN/P-specific IgE (sIgE) between 2016 and 2018. The TN/A FA diagnosis was assumed in the presence of: a) a suggestive FA clinical history or positive oral provocation test (OPT) and b) positive sIgE and/or skin prick tests (SPT) for the suspected foods. Statistical analysis was performed using SPSS program, with p<0.05 accepted as significant.
Results: We evaluated a total of 148 patients, of whom 36 were excluded (16-eosinophilic esophagitis, 14-incomplete data and 6-FA/sensitization excluded). Sensitization occurred in 112 patients, 13 of whom never ate TN/P and 15 had asymptomatic sensitization without allergy to any TN/P. The remaining 84 patients were diagnosed with FA (3 with positive OPT), with a total of 129 reactions. Forty-nine patients had a reaction to 1 TN/P, 19 to 2, 10 to 3, 1 to 4, and 1 to 7. In 4 patients the implicated TN/P couldn’t be identified. Of the 129 reactions, 50% had mucocutaneous symptoms, 5% respiratory, 5% gastrointestinal, and 39% anaphylaxis. There was no statistically significant difference between sIgE level and the severity of symptoms (anaphylaxis versus isolated symptoms). Of the 84 patients with FA, 36 reacted to walnut, 28 to peanuts, 16 to hazelnuts, 11 to almonds, 11 to cashews, 9 to pistachio seeds, 5 to sesame seeds, 5 to sunflower seeds and 4 to pine nuts. Of these, 45 patients tolerate at least 1 TN/P and in 39 tolerance is unknown (do not eat TN/P). In 49 of 84 patients, sensitization to molecular allergens was evaluated. The sIgE levels of patients with confirmed FA vs those with asymptomatic sensitization to walnuts (4.03 vs 0.18) and peanuts (2.72 vs 1.07) revealed a statistically significant difference. In other TN/P, the number of patients is insufficient to draw conclusions. There were 31 OPT: 3 positives and 28 negatives. Regarding negatives OPT, in 12 (43%) there was positive sIgE for the tested foods.
Conclusions: In our population, walnut was the most frequently involved TN/P FA, as described in the literature. When assessing TN/P FA it is important to quantify sIgE because higher levels were associated with FA. The positivity of sIgE does not exclude tolerance and therefore the OPT are mandatory in the diagnostic confirmation, especially if the clinical history is not clear.