S6352 Gastric Rust: A Rare Case of Erosive Gastritis From Oral Iron Therapy

Introduction: Iron pill-induced gastritis is an underrecognized cause of gastrointestinal (GI) distress in patients receiving oral iron therapy. This condition is relatively rare but has significant clinical implications. Its pathophysiology involves the direct toxic effect of iron on the gastric mucosa, leading to necrosis, ulceration, and ischemia. Herein, we present a case of iron pill-induced gastritis as a unique complication of oral iron supplementation. Case Description/Methods: An 85-year-old woman with a medical history of type 2 diabetes mellitus, hypertension, and iron deficiency anemia on iron supplementation was brought to the emergency department for altered mental status. Although the patient denied any acute complaints, she was only oriented to self and refusing to eat. No facial asymmetry, pathological drooling, pronator drift, or dysarthria was observed on examination. Triage labs: troponin, 343 pg/mL (reference range, 3-17) and blood glucose, 69 mg/dL (reference range, 70-110). The rest of the hemogram results were normal. Given the absence of an acute ischemic pattern on electrocardiogram, the troponin level was attributed to demand ischemia and trended down with subsequent labs. The patient was admitted for hypoactive delirium due to an acute urinary tract infection and was treated with antibiotics. Overnight, the patient had 2 melenic stools, and hemoglobin level dropped from 12.4 g/dL to 9.8 g/dL. The patient was resuscitated with IV fluids and high-dose PPIs. Although iron supplements are known to cause black or dark stools, an acute drop in hemoglobin level prompted further workup. Esophagogastroduodenoscopy (EGD) revealed erythematous mucosa in the gastric fundus and a few angioectasias with bleeding in the gastric fundus that were treated with argon plasma coagulation. Histological sections from the gastric fundus showed gastric mucosa with a yellowish-brown crystalline material embedded in the superficial epithelium, consistent with iron pill-induced gastritis. Iron supplementation was discontinued, and the patient continued on proton pump inhibitors for symptomatic relief. Discussion: There is a paucity of data on iron pill-induced gastritis in patients receiving therapeutic doses of iron, and the current evidence is limited to case reports and abstracts. Given the increasing prevalence of iron supplementation in diverse patient populations, clinicians should be aware of this rare but serious complication.