Background Food hypersensitivity (FH) is commonly suspected, especially among adults with atopic diseases. Symptoms of FH vary from oral allergy syndrome (OAS) to gastrointestinal, respiratory and systemic reactions. More data are needed regarding patient groups at risk for FH, and symptoms and foods responsible for the reactions.
Methods FH was studied in 286 Finnish university students. Four study groups were selected: subjects (i) with current atopic dermatitis (AD) with or without allergic rhinoconjunctivits (ARC) or asthma (n = 41); (ii) with past AD with or without ARC or asthma (n = 89); (iii) with ARC or asthma (n = 69); (iv) without clinically confirmed atopic disease (n = 87). A thorough clinical examination was performed with a questionnaire specifying adverse events to foods. In addition, IgE specific to five foods, and skin prick tests to four foods were determined.
Results FH was reported by 172 subjects (60.1%), more often by females (66.3%) than by males (47.9%) (P = 0.003). FH was most frequent among subjects with AD, among those with current AD in 73.2%, with past AD in 66.3%, and with ARC or asthma in 63.8%; 44.8% of subjects without any atopic disease reported FH. Kiwi fruit caused symptoms most frequently (38.4%), followed by milk (32.6%), apple (29.1%), tomato (27.9%), citrus fruits (25.0%), tree nuts (23.3%), and peanut (17.4%). A total of 720 separate symptoms to 25 food items were reported. OAS was most common (51.2%), followed by gastrointestinal symptoms (23.5%), worsening of AD (11.4%), urticaria (4.2%), rhinitis or conjunctivitis (5.7%) and asthma (4.0%). Severe reactions occurred in 3.5% (25/720). Negative IgE and skin prick test to foods predicted well negative history, but the value of positive test results was limited.
Conclusions FH was reported most often by students with current AD and multiple atopic diseases. Severe reactions occurred especially in patients with ARC and asthma. After excluding lactose intolerance, milk hypersensitivity was frequently reported.