Collagenous and lymphocytic gastritis in pediatric patients. A single-center experience observing an increase in diagnosis in recent years.

Background: Collagenous gastritis (CG) and Lymphocytic gastritis (LG) are rare types of gastritis. Thick sub-epithelial collagen bands characterize CG. Numerous lymphocytes in the surface and foveolar epithelium characterize LG. We aimed to characterize these disorders in our pediatric unit.

Methods: A retrospective review of children diagnosed with CG and LG between 2000 and 2023. Baseline data; demographics, anthropometric, symptoms, laboratory data, macroscopic and histopathologic findings. Follow-up data; treatment, improvement of symptoms and laboratory parameters.

Results: We identified 31 children, 11 (35.5%) had CG and 20 (64.5%) LG, mean age 9.07 ± 5.04 years. Seven (22.6%) children were diagnosed between 2000 and 2016 and 24 (77.4%) between 2017 and 2023. Baseline characteristics included gastrointestinal symptoms in 16 (51.6%), iron deficiency anemia in 22 (71%), with a mean hemoglobin level of 8.8 ± 2.5 gr/dl. Gastric endoscopic findings were normal in 12 (38.7%), demonstrated nodularity in 14 (45.2%) and an inflamed mucosa without nodularity in 5 (16.1%). Helicobacter pylori was positive in 3 (9.7%) children, celiac disease was diagnosed in 7 (22.6%). Treatment included iron supplementation in 24 (77.4%), proton pump inhibitors in 16 (51.6%) and a gluten free diet in seven. Mean follow-up was 2.9 ± 2.2 years. Hemoglobin levels normalized in 21/22; however, 9 (29%) patients required repeat iron supplementation. Eight patients had a repeat endoscopy (6 CG and 2 LG) without changes in their gastric histopathology.

Conclusions: CG and LG are not rare in pediatric patients. Physicians and pathologist should be aware of these types of gastritis.