Diagnostic Approach to Pediatric Collagenous Gastritis Based on a Case Series and Literature Review.

PURPOSE: Collagenous gastritis (CG) is a rare pediatric disorder characterized by gastrointestinal symptoms and iron-deficiency anemia. Owing to its low prevalence and broad range of nonspecific manifestations, CG is frequently overlooked during diagnosis. This study aimed to propose a diagnostic algorithm for CG and systematically review the published literature.

METHODS

Four patients aged <18 years diagnosed with CG at a tertiary referral center in Korea between 2003 and 2023 were retrospectively analyzed. In addition, 73 pediatric cases reported worldwide between 1989 and 2024 were reviewed.

RESULTS

Among 77 cases, excluding one case without symptom data, 16 patients (20.8%) had no gastrointestinal symptoms other than anemia. Abdominal pain was reported in 37 patients (48.7%), gastrointestinal bleeding in five (6.6%), vomiting in nine (11.8%), and diarrhea in three (3.9%). Anemia was present in 62 patients, and 68 tested negative for Helicobacter pylori. Most patients demonstrated nodular or irregularly coarse gastric mucosa on esophagogastroduodenoscopy (EGD), although these findings were less apparent during the early disease stage.

CONCLUSION

CG remains a diagnostically challenging condition that requires a high index of suspicion. Early EGD should be considered in pediatric patients with recurrent gastrointestinal symptoms and treatment-refractory iron-deficiency anemia who test negative for H. pylori. Careful evaluation for gastric mucosal nodularity and acquisition of additional histologic biopsies are recommended in these cases.