Allergic gastritis

**Definition:** Gastritis due to allergic disorders, principally meaning acute gastritis that occurs secondary to food allergy. But this also includes allergic gastritis due to non-food substances and allergic gastritis due to non-IgE-mediated hypersensitivity. This includes gastroduodenitis and gastroenteritis.

**Exclusions:** - Allergic eosinophilic gastritis - Food-induced eosinophilic gastroenteritis