Clinical inquiries. What is the best test to detect herpes in skin lesions?

Test ulcers with culture or PCR Genital and oral lesions consistent with herpes simplex lesions are relatively common in my practice. Before PCR testing was available, ulcers could be tested via culture—which took too long to be immediately useful—or via Tzanck smear, which helped greatly if multinucleated giant cells were seen. However, both tests were relatively insensitive. As this Clinical Inquiry demonstrates, ulcers currently should be tested either with culture or with PCR. Herpes culture is most sensitive if vesicles are still intact for unroofing.