Family history as a risk factor for herpes zoster: a case-control study.

OBJECTIVE: To assess risk factors for herpes zoster beyond age and immunosuppression, especially the association with a family history of herpes zoster, since a preventative herpes zoster and postherpetic neuralgia vaccine is now available.

DESIGN: We undertook a case-control study of herpes zoster, which represents reactivation of latent varicella zoster virus residing in dorsal root ganglia following primary infection, involving 504 patients and 523 controls. Interviews were conducted by trained medical investigators using a structured questionnaire.

SETTING: The Center for Clinical Studies, an outpatient clinic and research center in Houston, Texas.

PARTICIPANTS: Nonimmunocompromised patients with confirmed cases of herpes zoster were included in the study. Controls were nonimmunocompromised clinic patients with new diagnoses of skin diseases other than herpes zoster.

RESULTS: Cases were more likely to report blood relatives with a history of zoster (39%) compared with controls (11%; P < .001). Risk was increased with multiple blood relatives (odds ratio, 13.77; 95% confidence interval, 5.85-32.39) compared with single blood relatives (odds ratio, 4.50; 95% confidence interval, 3.15-6.41).

CONCLUSIONS: The results suggest an association between herpes zoster and family history of zoster. Future studies will be needed to investigate this association.