Herpes Gastritis: A Rare Cause of Gastric Outlet Obstruction

ABSTRACT

Introduction: Gastrointestinal tract involvement from herpes simplex virus is commonly associated with esophagitis. However, herpes simplex infection of the stomach is very rare with only a handful of cases being reported in immunocompromised patients. We present a case of herpes gastritis causing gastric outlet obstruction in an otherwise healthy, immunocompetent individual. Case Description/Methods: A 37-year-old male with a recent past medical history of COVID-19 infection, presented to the hospital with intractable nausea, vomiting, bloating, and early satiety for two days. Upon evaluation, CBC and CMP were remarkable for a WBC of 12.5 k/mm3 and ALT and AST of 124 U/L and 129 U/L, respectively. Lipase was 373 U/L. A CT abdomen/pelvis w/contrast showed circumferential wall thickening with edematous changes in the antrum consistent with localized inflammatory response. There was suspicion for gastric lymphoma and patient was admitted for further workup. An EGD was performed which showed exudative esophagitis and antral wall edema with luminal narrowing of gastric antrum. Endoscopic ultrasound (EUS) showed a 2.5 x 3 cm antral wall lesion worrisome for linitis plastica. Esophageal biopsies showed focal cytologic changes consistent with herpes esophagitis. The FNA of the gastric antral wall showed multinucleation of the basal cell layer with classic ground glass nuclei, consistent with herpes infection. No dysplasia or malignancy was seen. Both HSV1 and HSV2 IgG were elevated. HSV IgM was normal. A HSV PCR was ordered but never resulted. Patient was started on Valacyclovir 1 g PO BID for 10 days. He underwent a follow-up EGD 3 months later which showed complete resolution of the gastric antral changes (Figure). Discussion(s) Herpes gastritis is extremely rare. Literature review has revealed only 3 case reports of herpes gastritis;and all involved immunocompromised patients. To the best of our knowledge, this is the first case of herpes gastritis in an immunocompetent patient. Our patient presented with symptoms of gastric outlet obstruction which was caused by local inflammation from herpes simplex. It is unclear if having a COVID 19 infection altered patient's immunity and lead to herpes gastritis. This may need further investigation. No established guideline exists for treatment duration. Our patient received 10-day course of Valacyclovir, and his symptoms improved. Furthermore, patient had complete resolution of the herpes infection on follow-up EGD, indicating adequate treatment response.