Rapid detection and distinction of cutaneous herpesvirus infections by direct immunofluorescence

Abstract

Background: Optimal management of cutaneous herpes simplex virus (HSV) and varicellazoster virus (VZV) infections requires rapid, accurate distinction between these pathogens. Objective: In a mixed-case series of suspected cutaneous herpesvirus infections, we compared the diagnostic utility of viral culture and direct immunofluorescence (DIF) using a panel of fluoresceinated monoclonal antibodies against HSV and VZV. Methods: Epifluorescence microscopy of smears and viral culture were performed in parallel on 58 lesions. Results: DIF and culture were equally sensitive (88%) in HSV infections, whereas DIF was four times as sensitive as culture (100% vs 18%) in VZV. DIF either refuted an incorrect clinical diagnosis or permitted definitive laboratory diagnosis of a clinically indeterminate lesion in 7 (12%) of 58 lesions tested. Conclusion: DIF is a rapid, simple, sensitive, specific, cost-effective, and clinically useful technique for detecting and distinguishing cutaneous HSV and VZV infections.