Tzanck smears in herpes simplex virus infections

Background: The diagnosis of herpes simplex virus may require virological confirmation. Tzanck smear is an old, rapid, cost effective but nonspecific method that has been recently re-evaluated as a method for the diagnosis of herpes virus infection. This study was conducted to compare Tzanck smear and viral culture in the diagnosis of herpes simplex virus infection in patients clinically suspected to be infected with this virus. Method: Materials obtained from a fresh vesicle were used to prepare Tzanck smears and viral cultures. Result: In this study, 40 (71.4%) of the 56 samples were culture positive while Tzanck smears were positive in 36 (64.3%) patients. We found that the sensitivity and specificity of the Tzanck test was 90% and 100% respectively when compared to cell culture. Moreover, the positive predictive value (PPV) and negative predictive value (NPV) of the Tzanck test was 100% and 80%, respectively. Conclusion: The Tzanck smear has its limitations but is still a suitable rapid, easy, and cost effective diagnostic method for herpes simplex virus infections, especially when viral culture or other virological methods are not available.