Track

Clinical Studies

Abstract

Immunohistochemical staining (IHC) is commonly used for diagnosing herpes simplex virus (HSV) and varicella zoster virus (VZV) in the setting of a vesicular eruption. There are limited studies comparing the efficacy of viral IHC staining versus viral cultures (VC) and/or HSV/VZV PCR as a gold standard. In our study, we attempt to characterize the use of viral IHC staining in a private practice setting. Sixty patients with biopsies who underwent HSV/VZV IHC from January 1, 2014 to February 1, 2024 were identified. Those patients who did not have a VC or PCR test were excluded. The final cohort consisted of 10 patients, of whom 5(50%) were male with an average age of 43.1±20.43 years. Results include sensitivity of 100.00%, specificity of 33.33 %, positive predictive value of 77.78%, and negative predictive value of 100.00%. PCR and VC were both considered gold standard in our study; however, PCR has a higher sensitivity than VC and as such is more commonly used. IHC shows high sensitivity suggesting that it would have few false negatives relative to VC/PCR. The low specificity found could be due to limited sample size. Of note, the remaining 50 patients were diagnosed with HSV/VZV immunostaining alone. As such, it appears that pathologists are more likely to utilize IHC for HSV if they find suggestive cytopathologic findings on routine histopathology. A larger cohort study is required to further assess the accuracy of HSV/VZV immunostains.