Clinical Characteristics of Non-IgE-Mediated Gastrointestinal Food Allergy: Analysis of Nation-Wide Web-Based Online Patient Registry

Rationale: Cases of non-IgE-mediated gastrointestinal food allergy (non-IgE-GI-FAs) have increased dramatically in Japan since 2000. The most recently determined incidence rate was 0.21%. We established a nation-wide Web-Based Online Patient Registry in order to elucidate the clinical characteristics of non-IgE-GI-FAs.

Methods: Pediatricians all over Japan registered 718 patients from December 2009 through April 2014. We investigated 362 patients whose age at onset was less than 12 months and who fulfilled at least 4 of Miceli Sopo’s 5 diagnostic criteria. Clinical symptoms, signs, laboratory data and responses to treatments were analyzed.

Results: Based on the initial symptoms, the patients were classified into 4 clusters according to our previous study (JACI 2011). Ninety-two patients were classified as food-protein-induced enterocolitis syndrome (FPIES) with bloody stool (Cluster 1), 69 were FPIES without bloody stool (Cluster 2), 67 were food-protein-induced enteropathy (Cluster 3) and 131 were food-protein-induced colitis (Cluster 4). Patients in Cluster 1 showed significantly earlier onset (median: 8 days after birth). Serious complications (ileus, intestinal perforation, etc.) were observed in 6.1% of the total patients, and the highest rate (13%) was in Cluster 1 patients. Milk-specific IgE was detected in 17% of the total population, with the lowest rate (5%) in Cluster 4 patients. Amino acid-based formula reduced the symptoms most effectively in all clusters.

Conclusions: FPIES with bloody stool was characterized by earlier onset and the highest incidence of serious complications among the 4 clusters of non-IgE-GI-FAs. Early diagnosis and treatment seem to be essential for infants with FPIES with bloody stool.