Characterization of pediatric eosinophilic gastrointestinal disorders beyond eosinophilic esophagitis in a nationwide cohort

Objectives: Nonesophageal eosinophilic gastrointestinal disorders (non-EoE EGIDs) are rare, underrecognized inflammatory diseases of the gastrointestinal (GI) tract, especially in children. Their clinical heterogeneity and lack of specific biomarkers contribute to diagnostic delays and therapeutic challenges. Methods: This retrospective multicenter study included pediatric patients (<18 years) diagnosed with non-EoE EGIDs across 12 Italian centers affiliated with the Italian Society of Pediatric Gastroenterology Hepatology and Nutrition (SIGENP). The data were retrospectively collected from January 2012 to December 2022. Diagnosis was based on ESPGHAN histological criteria. Clinical, laboratory, endoscopic, and histological data were collected at baseline and during follow-up. Treatment modalities and outcomes were analyzed. Results: A total of 86 patients (71% male; median age 10.5 years) were included. The stomach was the most commonly involved site (45.4%), followed by the small bowel (40.7%) and colon (24.4%). Multiple segment involvement occurred in 45.4% of cases. Abdominal pain (64.9%) and diarrhea (38.2%) were the most common symptoms, with diarrhea significantly associated with colonic involvement. Laboratory findings showed peripheral eosinophilia in 50% of patients and hypoalbuminemia in those with multisegment involvement. Very early-onset EGIDs (>1 and <2 years) were associated with features such as predominant colonic involvement and anemia. Treatment responses varied: 50% achieved clinical remission after first-line therapy (proton pump inhibitors, topical/systemic steroids, or elimination diets). Among 61/86 patients who underwent endoscopic follow-up, 49.2% achieved macroscopic remission and 40.9% histological remission. Conclusions: Pediatric non-EoE EGIDs present with heterogeneous symptoms and variable tract involvement. Younger children show distinct phenotypes. Laboratory findings are nonspecific and have limited diagnostic utility. Treatment remains challenging, with suboptimal response rates. These findings underscore the need for prospective studies.