Search

Background: Food allergy is a growing health concern with a prevalence of 2%–3% in the adult population in Europe. Non‐immune‐mediated food hypersensitivities, which include reactions after ingestion of food additives, affect 1% of adults and may resemble IgE‐induced allergic reactions without identifiable immunologic sensitization. A double‐blind placebo‐controlled food challenge (DBPCFC) is the gold standard for the diagnosis of any food hypersensitivity. Objective: We analysed a large group of adult patients with suspected food hypersensitivity, who had undergone DBPCFC, to better understand IgE‐mediated food allergy and non‐immune‐dependent food hypersensitivity to food additives in adults regarding elicitors, symptoms and positivity rates of oral challenges. Methods: Data from 541 patients with suspected food hypersensitivity were analysed, who underwent an oral food challenge between 2010 and 2019. Results: IgE‐dependent food allergy was confirmed in 114 of 329 adult patients (34.6%). The confirmation rate was lower in the group of patients with suspected non‐immune‐mediated reactions to food additives (65 of 286, 22.7%). Urticaria and angioedema appeared more frequently in patients with IgE‐mediated food allergies. By contrast, flush and diarrhoea were the most frequent symptoms after a challenge in the group with the non‐immune‐mediated reactions to food additives. Wheat and celery were the most frequently identified food allergens in adults, whereas colourings and preservatives were the most frequent elicitors of non‐immune‐mediated food hypersensitivity. Conclusion: The importance of oral food challenges for the diagnosis of food hypersensitivity is confirmed. IgE‐dependent food allergy is more frequently proven, reaching a positivity rate of one‐third and only about 20% for non‐immune‐mediated hypersensitivity. Future studies should elaborate on the mechanisms of non‐immune‐mediated food hypersensitivity and the clinical impact of cofactors in this setting. [ABSTRACT FROM AUTHOR]

Background: Systemic allergic reactions to vaccines are very rare. In this study we assessed the management and outcome of suspected SARS‐CoV‐2 vaccine hypersensitivity. Methods: Totally, 334 individuals underwent an allergy work up regarding SARS‐CoV‐2 vaccination (group A: 115 individuals suspected to be at increased risk for vaccine‐related reactions before vaccination and group B: 219 patients with reactions after COVID vaccination). The large majority of the SPT/IDT with the vaccines were negative; however, we identified in 14.1% (n = 47) a possible sensitization to the SARS‐CoV‐2 vaccine and/or its ingredients defined as one positive skin test. Of the 219 individuals (group B) who experienced symptoms suspicious for a hypersensitivity reaction after vaccination, 214 were reported after the first vaccination with a mRNA vaccine (157 mRNA (Comirnaty®, 38 Spikevax®) and 18 with a vector vaccine (Vaxzevria®), 5 cases were after the second vaccination. Results: The symptom profile in group B was as follows: skin symptoms occurred in 115 cases (n = 59 angioedema, n = 50 generalized urticaria and n = 23 erythema/flush. Seventy individuals had cardiovascular, 53 respiratory and 17 gastrointestinal symptoms. Of the overall 334 individuals, 78 patients tolerated (re)‐vaccination (out of skin test positive/negative 7/19 from group A and 17/35 from group B). Conclusion: Proven IgE‐mediated hypersensitivity to SARS‐CoV‐2 vaccines is extremely rare and not increased in comparison with reported hypersensitivity to other vaccines. The value of skin tests is unclear and nonspecific reactions, in particular when intradermal testing is applied, should be considered. [ABSTRACT FROM AUTHOR]