Oropharyngotonsillitis associated with nonprimary Epstein-Barr virus infection

Objective: To identify distinct clinical features of pharyngotonsillitis or oropharyngitis associated with Epstein-Barr virus (EBV) infection from her pes simplex virus infection. Design: Clinical studies by case exploration. Setting: Institutional practice at a university hospital. Patients: Thirty-three patients with pharyngotonsillitis and 4 patients wit h oropharyngitis of nonbacterial infection underwent biopsy of pharyngotons illar lesions. Main Outcome Measure: The specimens were examined by histopathology, immuno histochemistry, in situ hybridization, and polymerase chain reaction. In ad dition to serological testing and routine laboratory data, photographic oro pharyngeal findings were collected for clinical evaluation. Results: In situ hybridization to detect EBV-encoded small nuclear RNA-1 an d -2 disclosed 8 cases of pharyngotonsillitis and 4 cases of oropharyngitis associated with EBV infection. Immunohistochemical analysis identified 5 c ases of pharyngotonsillitis associated with herpes simplex virus infection. Serological examination showed that, among 12 cases positive by in situ hy bridization, 3 cases were primary infection with infectious mononucleosis a nd 9 were nonprimary infection. The staining pattern of in situ hybridizati on was different, ie, a linear pattern in cases of nonprimary infection and a scattered pattern in cases of primary infection. The clinical manifestat ions of EBV pharyngotonsillitis were distinct from those of herpes simplex virus pharyngotonsillitis and were characteristic irrespective of infectiou s status, while those of EBV oropharyngitis were more variable. Conclusions: Epstein-Barr virus-associated pharyngotonsillitis was demonstr ated in patients with nonprimary infection unaccompanied by infectious mono nucleosis. Epstein-Barr Virus should be considered a potential causative ag ent of oropharyngotonsillitis even in absence of infectious mononucleosis, especially in a young adult.