PRESENTATION, CLINICAL COURSE AND OUTCOME IN PEDIATRIC COLLAGENOUS GASTRITIS

Introduction: Collagenous gastritis (CG) is a form of rare gastrointestinal condition characterized by increased subepithelial collagen deposition and mixed lamina propria inflammation including eosinophils.The pathophysiology is poorly understood and treatment has been based largely on small case series.We present the largest single-institution case series to date, describing the presentation, treatments and outcomes of pediatric CG.Method: A retrospective cohort study was performed of patients diagnosed with CG between 1992-2018.Clinical data was obtained from medical records.Results: Patient population: 33 patients (54.5% female) were identified.Mean age was 11.3±4.2years (2.5-18 yrs) and mean duration from symptom onset to diagnostic esophago-gastro-duodenoscopy (EGD) was 1.8 yrs (0.5 mo-8 yrs).Autoimmune comorbidities were found in 24.2% and a family history of autoimmunity in 45.5% of patients.Presenting symptoms: Presenting symptoms included abdominal pain (59%), anemia (46%), vomiting (27%), nausea (27.3%), poor growth/weight gain (14%), diarrhea (9%), fatigue (9%), weight loss (9%), gastrointestinal bleed (9%), distension (5%) and dysphagia (5%).Endoscopic findings: The diagnostic EGD was abnormal in all patients, showing gastric nodularity (88%), erythema (32%), friability (24%), granularity (12%),adherent blood (8%), furrowing (4%) or ulcers (4%).39% of patients had undergone an EGD a mean of 2.7 years prior to diagnosis (1mo-7.8yrs) for the same symptoms which ultimately led to the diagnosis of CG, showing chronic inactive gastritis in 85%, increased lamina propria eosinophils in 39%, intraepithelial migration of eosinophils in 23% and was normal in 7.7% of patients.Treatment: Summarized in Table 1.Outcome: At last follow-up (2.5±2.4yrs),50% of patients were asymptomatic, 46.6% improved and 3.6% had persistent symptoms.All patients with anemia had resolution, 21.4% on and 68.4% off iron supplemenation.42% had follow up EGDs at 2.6±1.9 years (4 mo-5.3 yrs) after diagnosis.Persistent sub-epithelial collagen on the last EGD was found in 78.5%.Conclusion: CG is rare.Most commonly, patients present with abdominal pain, anemia, nausea, and vomiting; gastric nodularity is typically seen endoscopically at the time of diagnosis.Although there are no established treatment standards, in this largest single institution case series to date, we show that all anemic patients responded to iron supplementation, and thus iron supplementation is a recommended treatment option in this patient subset.A variety of medications aimed towards inflammation and symptomatic treatment were used; however, anti-inflammatory drugs are not clearly efficacious in CG.Despite persistent findings of increased sub-epithelial collagen deposition at the last follow-up endoscopy, nearly all patients show remission or resolution of clinical symptoms over time.