What is the best test to detect herpes in skin lesions?(CLINICAL INQUIRIES)

EVIDENCE-BASED ANSWER

Polymerase chain reaction (PCR) techniques appear to be more sensitive and specific in detecting herpes simplex virus (HSV) in genital lesions (strength of recommendation [SOR]: A, based on 2 diagnostic cohort studies); however, viral culture remains the gold standard (SOR: C, based on expert opinion). Studies of serologic and antibody detection tests report higher sensitivities than viral culture (SOR: C, based on consensus guidelines). Cytologic tests such as the Tzanck smear and Papanicolaou (Pap) smear have poor sensitivities and specificities and should not be relied upon for a diagnosis of genital herpes (SOR: C, based on expert opinion).

CLINICAL COMMENTARY

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 …