S4183 Pill Impaction Unmasking Eosinophilic Esophagitis and Acute Ulcerative Herpes Simplex Esophagitis in an Immunocompetent Patient

Introduction: Eosinophilic esophagitis (EoE) is a chronic Th2-mediated inflammatory disorder characterized by esophageal remodeling and food impaction. While secondary infections are rare, mucosal disruption may predispose patients to superimposed pathogens. Herpes simplex virus (HSV) esophagitis typically affects immunocompromised hosts, but its coexistence with EoE in immunocompetent individuals is extremely rare. We present a unique case where pill impaction revealed undiagnosed EoE with superimposed HSV esophagitis in a previously healthy adult. Case Description/Methods: Forty-year-old man with seasonal allergies presented with fever, odynophagia, poor appetite, nausea and vomiting. He was administered oral potassium chloride for mild hypokalemia, which became lodged in his chest. Esophagogastroduodenoscopy revealed an impacted pill at 20–22 cm, which was removed. A severe 8 mm esophageal stricture was dilated, and characteristic EoE findings were noted: trachealization, exudates, furrows, and edema. The EoE Endoscopic Reference Score was notable for grade 3 rings and grade 2 exudates. Histology confirmed >55 eosinophils per high-power field in the distal esophagus and 37 proximally, consistent with EoE. Immunohistochemistry revealed intranuclear HSV inclusions, confirming superimposed HSV esophagitis. HIV and other immunosuppressive workups were negative. The patient was treated with oral valacyclovir and proton pump inhibitor therapy. Despite counseling, he was lost to follow-up. Discussion: This case illustrates how mechanical mucosal trauma (e.g., pill impaction) in a fibrostenotic esophagus can unmask underlying EoE and precipitate superinfection. HSV esophagitis in immunocompetent hosts is rare and may occur due to impaired barrier function in EoE. Chronic inflammation, dysbiosis, and Th2 cytokine dysregulation may facilitate viral invasion despite preserved systemic immunity. Dual esophageal pathology—EoE and HSV esophagitis—can occur even in immunocompetent individuals and may be revealed by sentinel events such as pill impaction. Early endoscopy with biopsy is essential to guide targeted therapy. This case reinforces the evolving understanding of mucosal vulnerability in EoE and the need for vigilance in patients presenting with acute esophageal symptoms.