Early diagnosis of virus-caused vesicular rashes by immunofluorescence on skin biopsies. I. Varicella, zoster and herpes simplex.

The use of immunofluorescence (IF) for the rapid identification of varicella-zoster (V-Z) and herpes simplex (HS) antigen in frozen sections of biopsies of early non-vesicular skin lesions was investigated. Direct IF, using fluorescein- isothiocyanate- conjugated immuoglobulin (FITC Ig) of paired human anti-V-Z sera and FITC-conjugated negative and positive anti-V-Z-monkey Ig, yielded specific fluorescence of virus antigen in all 14 varicella cases investigated and in 10/11 zoster cases. In contrast, indirect IF, using paired human anti-zoster sera and a sheep anti-human Ig FITC, was not satisfactorily specific, since staining with the anti-human Ig FITC alone also yielded fluorescence of infected cells in some cases. In 6/8 cases of HS infection, specific fluorescence of virus antigen was obtained by direct IF, using FITC-conjugated negative and positive guinea-pig anti-HS Ig. Because of the often predominant distribution of virus antigen to the corium and the skin appendages, punch biopsies are apparently better than scraped material, at least in the prevesicular stage.