Clinical features of food protein-induced enterocolitis syndrome.

OBJECTIVE: To describe the clinical characteristics of food protein-induced enterocolitis syndrome (FPIES), a symptom complex of severe vomiting and diarrhea occurring several hours after the ingestion of particular food proteins in infants. STUDY DESIGN: Retrospective review of a referral population. RESULTS: Sixteen patients had typical FPIES; 11 reacted to milk, 11 to soy, and 7 to both. Mean age at diagnosis was 7 weeks for milk reactivity and 8 weeks for soy reactivity. Two patients also had rice- and pea-induced FPIES. Among 14 patients who were followed up for a median period of 25 months, loss of sensitivity to milk occurred in 6 of 10 patients and loss of sensitivity to soy occurred in 2 of 8. Six additional cases of FPIES were considered atypical: 1 patient had late-onset disease caused by poultry, and in 5 patients IgE antibody to milk or soy developed. During supervised food challenges with milk and soy, the peripheral blood neutrophil count rose over 3500 cells/mm3 in 9 of 10 positive challenges and did not rise above this value in the 7 negative challenges. Emergency treatment was required in 62% of challenges. CONCLUSIONS: Although most patients with FPIES are infants reactive to milk and/or soy, this diagnosis should be considered in older children and for other foods. Food-specific IgE sensitivity may develop in some patients. Standardized food challenges are helpful for diagnosis and follow-up.