Food allergy-related paediatric constipation: the usefulness of atopy patch test.

The aims of this study were to evaluate the implication of food allergy as a cause of paediatric constipation and to determine the diet period needed to tolerate the constipation-causing foods. Fifty-four children aged 6 months to 14 years (median, 42 months) suffering from chronic constipation (without anatomic abnormalities, cοeliac disease or hypothyroidism), unresponsive to a 3-month laxative therapy, were prospectively evaluated. All participants were evaluated for allergy to cow's milk, egg, wheat, rice, corn, potato, chicken, beef and soy, using skin tests (SPT), serum specific IgE and atopy patch test (APT). A withdrawal of the APT-positive foods was instructed. Thirty-two children had positive APT; 15 were positive to one; six, to two and 11, to three or more food allergens, wheat and egg being the commonest. After withdrawing the APT-positive foods for an 8-week period, constipation had improved in 28/32 children, but a relapse of constipation was noticed after an oral food challenge, so they continued the elimination diet. Tolerance to food allergens was achieved in only 6/28 after 6 months, compared to 25/28 after 12 months and to all after a 2-year-long elimination. Food allergy seems to be a significant etiologic factor for chronic constipation not responding to treatment, in infants and young children. APT was found to be useful in evaluating non-IgE allergy-mediated constipation, and there was no correlation of APT with IgE detection. Tolerance was adequately achieved after 12 months of strict food allergen elimination.