Association between family history and herpes zoster: a case-control study

There are many risk factors besides age and immune suppression for herpes zoster. Family history as a risk factor is suggested in some recent studies. The aim of this study was to evaluate the association between herpes zoster and family history.

This case-control study was undertaken in Farshchian Hospital, Hamadan, Iran. "Case group" included patients with confirmed diagnosis of herpes zoster. "Control group" was chosen among other dermatologic patients or their companions without any history of herpes zoster. Immune deficiency was the main excluding criteria. Information about age, gender, dermatome involved (only in patient group), history of chronic dermatologic or systemic diseases and family history of herpes zoster was asked using special questionnaires.

Case and control groups included 217 and 200 participants respectively. Mean age of cases and controls was 49.08±15.59 and 49.96±15.54 years old respectively (P=0.936). 53.5% of cases and 54.5% of controls were women (P=0.845). Most frequent dermatomes involved in patients were thoracic (85/217; 39.25%) and cervical dermatomes (55/217; 25.3%). Frequency of herpes zoster in first-degree blood relatives in cases and controls was 65/217 (30%) and 16/200 (8%) respectively (OR=4.91; 95% CI: 2.73, 8.85; P=0.001).

Our findings indicated a significantly higher proportion of patients with family history of herpes zoster comparing to controls. This study confirms family history as a risk factor for herpes zoster. Therefore, the old patients with positive family history of herpes zoster may be appropriate candidates for vaccination with Zostavax. However, more evidence based on large cohort studies in needed to confirm our findings.