Severe eosinophilic gastritis is associated with peripheral eosinophilia and multi-organ involvement

Histologic gastric eosinophilia (HGE), characterized by dense eosinophil infiltration in gastric mucosa, is an understudied disease with unclear etiology. Unlike its counterpart, eosinophilic esophagitis (EoE), which has defined diagnostic eosinophil thresholds and characteristic endoscopic findings, proposed eosinophil thresholds for the diagnosis of HGE vary and endoscopic findings are not well characterized. This study aimed to assess the clinical, histological, and endoscopic features of HGE in adults and children. A cohort of 50 HGE patients were identified (20 children, 30 adults; 58.0 % male). The majority (70.0 %) had an allergic/atopic history. Pediatric patients with HGE were significantly more likely to have a history of food allergy (P = 0.013) and less likely to have drug allergy (P = 0.001) compared to adults. The most common endoscopic finding was ulceration/erosion (34.0 %). Multiorgan GI-tract involvement was seen in 40.9 % of patients, primarily affecting the esophagus (39.0 %) and duodenum (15.4 %). HGE cases were stratified by severity into G1 (50-100 eosinophils/HPF; 11 patients) and G2 (>100 eosinophils/HPF; 39 patients) groups for comparison. Patients with G2 HGE had higher rates of peripheral eosinophilia (P = 0.010) and multiorgan GI involvement (P = 0.047) compared to those with G1 HGE. In conclusion, HGE often presents as a gastric ulcer and is strongly associated with food allergy in children and drug allergy in adults. Severe HGE is more likely than moderate HGE to present with peripheral eosinophilia and concomitant eosinophilia elsewhere in the GI tract, therefore, noting the presence of severe HGE may be helpful in guiding clinical follow up.