Geographic and racial aspects of herpes zoster.

Geographic and racial factors have been reported in studies of the epidemiology of varicella and herpes zoster. To clarify further these relationships, data from five multicenter clinical trials of the antiviral agent famciclovir were examined (total N = 2074). Non-Caucasian racial group and tropical region were each significantly associated with younger age at zoster onset. In analyses of the non-Caucasian subgroups, Black and Asian patients did not significantly differ in age or sex; however, Black and Asian patients from tropical regions had significantly younger mean ages at onset and greater rash duration at enrollment than those from temperate regions. Controlling for sex and rash duration at enrollment, both tropical region and non-Caucasian racial group were found to be independently associated with a younger age at zoster onset. These results suggest that racial group and geographic region may be independent factors associated with age at onset in patients with herpes zoster. Copyright 2003 Wiley-Liss, Inc.