The familial risk of acne vulgaris in Chinese Hans - a case-control study.

Background: Acne is a chronic inflammatory disease of the pilosebaceous follicles. Recent studies bring us increasing evidences that hereditary factors play an important but indirect role in acne.

Objective: To investigate the possible role of genetic factors in the pathogenesis of acne vulgaris in Chinese Han ethnic group.

Patients And Methods: Volunteers of 975 acne cases and 580 controls were included, contributing 3009 and 1825 first-degree relatives, respectively. One thousand and eighty-five first-degree relatives of acne cases were affected with facial acne. This compared with 223 first-degree relatives of non-acne controls. The odds ratio was used to estimate the relative risk for acne vulgaris associated with having an affected first-degree relative.

Results: The risk of acne vulgaris occurring in a relative of a patient with acne vulgaris was significantly greater than for the relative of an unaffected individual (odds ratio 4.05, 95% confidence interval (CI): 3.45-4.76, P<0.001).

Conclusion: Our study suggests that familial factors are important in determining individual susceptibility to acne vulgaris.