Clinical features:
(1) history of chemical or chronic drug exposure, most often NSAIDs
(2) endoscopic picture of moderate to severe gastritis
Histologic features:
(1) minimal inflammation (much less than expected based on endoscopic appearance)
(2) diffuse edema and fibrosis in the lamina propria
(3) mucus depletion
(4) villiform transformation
(5) pit expansion
(6) extension of smooth muscle fibers into the mucosa from the muscularis mucosae (this can be striking)
Features seen in other forms of gastritis that are typically absent:
(1) absence of metaplasia
(2) absence of micro-organisms if pure (see below)
(3) absence of polyps
(4) absence of enlarged folds
Differential diagnosis:
(1) Helicobacter pylori gastritis: This may co-exist with chemical gastropathy, in which case making the diagnosis can be difficult. Antibiotic therapy may unmask an underlying chemical gastropathy.
