The aim of this study was to determine the clinical significance of food-specific IgE antibody tests in detecting triggering antigens in food protein-induced proctocolitis (FPIPC).

Between February 2006 and May 2007, data from 16 consecutive FPIPC patients that underwent MAST and Uni-CAP tests on initial visits, were reviewed. The endoscopic criterion used for establishing a diagnosis of FPIPC was an increase in the number of eosinophils in the lamina propria (≥60 per 10 high power fields). Offending foods were suspected clinically based on elimination and challenge testing to mother or patient diets with the following five highly allergenic foods: dairy products, eggs, nuts and soybean, fish and shellfish, and wheat and buckwheat. We compared the results of initial MAST or Uni-CAP tests with clinically suspected offending foods.

For the 16 FPIPC patients, MAST tests showed positive results in 2 patients (12.5%), and Uni-CAP tests showed positive results in 3 patients (18.8%). Through clinical elimination and challenge, the 33 offending foods were identified: 7 fish and shellfish (21.2%), 6 eggs (18.2%), 6 wheat and buckwheat (18.2%), 4 dairy products (12.1%), 3 soybean (9.1%), 3 pork (9.1%), 2 nuts (6.1%), 1 beef (3.0%), and 1 mushroom (3.0%). Clinically suspected offending foods and MAST and Uni-CAP test results were found to be correlated in 1 patient (6.7%) each.

Food specific IgE antibody tests are inappropriate for predicting offending foods in FPIPC. Clinical food elimination and challenge testing provide useful means of detecting offending foods.