Herpes simplex primo-infection in an immunocompetent host with eosinophilic esophagitis.

Eosinophilic esophagitis and herpes simplex esophagitis are separately well-described entities, but their simultaneous occurrence may pose a special challenge to the clinician, especially regarding the optimal therapeutic approach. The following case report describes a patient with a history of cow's milk and dairy products intolerance, but without an underlying immunologic defect, in whom eosinophilic esophagitis was diagnosed in the course of primary herpes simplex virus 1 (HSV1) infection that clinically presented as herpes labialis and severe esophagitis. The diagnosis was confirmed by a polymerase chain reaction from cytological brush and by immunohistochemical staining that detected the presence of HSV1 DNA in esophageal mucosa, and histologically by persistent eosinophil-predominant inflammation, typical of eosinophilic esophagitis. Despite severe clinical presentation, the HSV1 infection was self-limited. After a directed elimination diet was introduced, the clinical course was favorable, without the need for antiviral therapy.