The diagnosis of herpes zoster often can be made from the clinical presentation, but other procedures may be necessary in atypical cases.
Viral culture can confi rm the clinical impression but takes at least 24 hours.
Cytologic smears demonstrate viral cytopathologic effects, as seen in varicella and HSV.
In most cases the clinical presentation allows the clinician to differentiate zoster from HSV, but cases of zosteriform recurrent HSV infection, although uncommon, do exist.
A rapid diagnosis can be obtained through the use of direct staining of cytologic smears with fl uorescent monoclonal antibodies for VZV.
This technique gives positive results in almost 80% of the cases.
Molecular techniques such as dot-blot hybridization and PCR also can be used to detect VZV.