Esophagitis

Pathophysiology varies by etiology: (1) Reflux esophagitis - acid/bile reflux due to LES dysfunction causes mucosal injury, basal zone hyperplasia, and elongation of papillae; chronic disease can lead to Barrett esophagus (intestinal metaplasia) and adenocarcinoma risk. (2) Infectious esophagitis - seen in immunocompromised (HIV/AIDS, transplant, chemotherapy) patients; Candida albicans produces white pseudomembranes/plaques (treat with fluconazole), HSV causes punched-out ulcers with multinucleated giant cells and Cowdry A inclusions, CMV causes linear ulcers with owl's eye inclusions in endothelial/stromal cells. (3) Eosinophilic esophagitis - allergic/atopic condition, presents in children/young adults with dysphagia and food impaction, biopsy shows >15 eosinophils/hpf, esophageal rings (trachealization), unresponsive to PPI alone; treated with topical steroids (fluticasone/budesonide) and dietary elimination. (4) Pill-induced esophagitis - doxycycline, bisphosphonates, NSAIDs, KCl causing direct mucosal injury, especially if taken without water or lying down. (5) Caustic esophagitis - from alkali/acid ingestion, risk of stricture. Clinical presentation includes odynophagia (painful swallowing), dysphagia, retrosternal burning pain, and in severe cases, bleeding or stricture formation. Diagnosis via endoscopy with biopsy; barium swallow may show 'feline esophagus' in eosinophilic esophagitis or ringed esophagus. Complications include strictures, Barrett esophagus, and esophageal cancer (adenocarcinoma from GERD/Barrett, squamous cell carcinoma from caustic injury).