S4288 Primary Herpes Simplex Virus Esophagitis in an Immunocompetent Young Adult: A Diagnostic Challenge

Introduction: Esophagitis commonly presents with odynophagia and dysphagia and is often attributed to reflux, infections, or medications. While uncommon, herpes simplex virus (HSV) esophagitis is among the differential and typically affects immunocompromised patients but can also rarely affect immunocompetent individuals, especially during primary infection. Due to its nonspecific presentation, it may be mistaken for other etiologies. This case highlights HSV esophagitis in a previously healthy, young adult. Case Description/Methods: A 24-year-old immunocompetent man presented with a 3-day history of high-grade fever and sore throat. On examination, he had purulent tonsillar exudates, and a provisional diagnosis of bacterial tonsillitis was made. He was started on amoxicillin-clavulanate. However, due to lack of improvement, noticeable tonsillar enlargement, and worsening odynophagia, treatment was escalated with clindamycin and dexamethasone. Over the following days, his symptoms progressed with increased odynophagia and reduced oral intake, prompting a gastroenterology referral. Further history revealed recent labial vesicles and oral ulcers. Notably, his wife had experienced a self-limited episode of herpes labialis shortly before his illness, raising suspicion for a primary HSV infection. HIV testing was negative, with no known immunodeficiency. Esophagogastroduodenoscopy revealed extensive esophageal ulcerations with white exudates, initially suspicious for Candida esophagitis. Empiric treatment with fluconazole, acyclovir, esomeprazole, and continued clindamycin was initiated. Histopathological examination of esophageal biopsies showed viral cytopathic changes including nuclear molding, multinucleation, and intranuclear inclusions consistent with HSV esophagitis. PAS staining was negative for fungal elements. After confirmation, only acyclovir (400 mg orally) and esomeprazole (40 mg orally) were continued. The patient’s symptoms resolved completely within 2 weeks. Discussion: HSV esophagitis, though rare in immunocompetent individuals, should be considered in cases of persistent odynophagia, especially in the context of recent HSV exposure and mucocutaneous lesions. In our case, recent corticosteroid use may have contributed by transiently impairing local immune defenses, allowing for more severe mucosal involvement during primary infection. Endoscopy and biopsy remain essential for diagnosis, and early antiviral treatment can lead to rapid resolution.