Grape allergy and co-sensitization to other food allergens

OBJECTIVE Reports of IgE-mediated allergic reactions to grapes and wine are limited. The object of this prospective study was to present in detail the clinical picture of patients with documented IgE mediated reactions to grape or its products and the co-sensitizations to other common food allergens among this specific population. METHOD The study group comprised 30 patients (13 males, 17 females), aged 16-44 years (mean 25.8 years) who were enrolled on the basis of a documented history of IgE-mediated reactions to grape or its products (wine, juice, wine vinegar). The evaluation consisted of: Full allergological data (personal and familial atopic history, the offending grape product for each reaction, the mean time between consumption and onset of symptoms, clinical signs, treatment), clinical examination, specific allergological in vivo testing (SPTs, prick to prick with positivity criteria wheal diameter >3 mm(2) and erythema > 10 mm(2)) and in vitro measurements (grape specific IgE determination with CAP, Pharmacia, in kU/L considering as positive values >0.35 kU/L). The allergological diagnostic procedure was extended to include other food allergens (tree nuts including peanuts, various species of fruits) and moulds that often contaminate fruit surfaces, in order to evaluate cosensitization. RESULTS Of the study group, 18/30 (60%) had a positive personal and 10/30 (33.3%) familial atopic history. Patients reported an average of 3.7 episodes/patient (range 1-15) after consumption of grape or its product and 22/30 (73.3%) had presented oral allergy syndrome (OAS) after eating grape before the first reported reaction. The mean time for the onset of symptoms was 55 min (5-150 min). More than one episode of grape allergy was reported by 24/30 (80%). The observed prevalence of symptomatology according to the system involved was: skin 29/30 (96.7%), respiratory 26/30 (86.7%), cardiovascular 14/30 (46.7%), gastrointestinal 11/30 (36.7%). The main co-sensitizations with other food allergens were: apple 80%, peach 76.7%, cherry 53.3%, strawberry 43.3%, peanut 60%, walnut 56.7%, hazelnut 36.7%, almond 26.7%, pistacchio 23.3%. CONCLUSIONS Grapes, wine and other grape products can cause serious allergic reactions in sensitized individuals. The high incidence of co-sensitization, especially to other fruit allergens, should be a basis for further investigation of pan-allergens in botanically unrelated species of fruits that might also be of clinical importance.