Double blind, placebo controlled food reactions do not correlate to IgE allergy in the diagnosis of staple food related gastrointestinal symptoms.

BACKGROUND: The mechanisms for adverse reactions to foods in the gastrointestinal tract are poorly understood. There is conflicting evidence in the literature on the role for IgE mediated allergy in gastrointestinal reactions to staple foods. AIM: The aim was therefore to study the role of IgE mediated allergy in a group of patients with a history of gastrointestinal symptoms related to staple foods (cows' milk, hens' egg, wheat and rye flour) verified in double blind placebo controlled challenges (DBPCFC). PATIENTS: Fifteen patients with DBPCFC, identified by screening of 96 consecutive patients referred to our allergy clinic for investigation of suspected gastrointestinal symptoms due to staple foods. METHODS: The screening included diaries as well as elimination diets and open and blinded food challenges. The frequency of atopy were compared between the double blind positive and double blind negative patients. RESULTS: The positive DBPCFC in the 15 patients included eight patients with milk intolerance, four with wheat flour, two with egg, and one with rye flour. There was no indications of an allergic pathogenesis in all 15 patients with positive DBPCFC, as the skin prick test and radioallergosorbent test were negative for the relevant allergens. The frequency of atopy was four of 21 (19%) in the double blind negative group and three of 15 (20%) in the double blind positive group. CONCLUSION: In adult patients with staple food induced gastrointestinal symptoms, objectively verified by DBPCFC, there were no indications of IgE mediated allergy to the relevant foods suggesting other mechanisms in adults than in children. Future studies may include measures of local events in the shock organs in relation to food intake, for instance utilising inflammatory markers in jejunal fluids.