Family history, body mass index, selected dietary factors, menstrual history, and risk of moderate to severe acne in adolescents and young adults

Background: Genetic and environmental components may contribute to acne causation. Objective: We sought to assess the impact of family history, personal habits, dietary factors, and menstrual history on a new diagnosis of moderate to severe acne. Methods: We conducted a case-control study in dermatologic outpatient clinics in Italy. Cases (205) were consecutive those receiving a new diagnosis of moderate to severe acne. Control subjects (358) were people with no or mild acne, coming for a dermatologic consultation other than for acne. Results: Moderate to severe acne was strongly associated with a family history of acne in first-degree relatives (odds ratio 3.41, 95% confidence interval 2.31-5.05). The risk was reduced in people with lower body mass index with a more pronounced effect in male compared with female individuals. No association with smoking emerged. The risk increased with increased milk consumption (odds ratio 1.78, 95% confidence interval 1.22-2.59) in those consuming more than 3 portions per week. The association was more marked for skim than for whole milk. Consumption of fish was associated with a protective effect (odds ratio 0.68, 95% confidence interval 0.47-0.99). No association emerged between menstrual variables and acne risk. Limitations: Some degree of overmatching may arise from choosing dermatologic control subjects and from inclusion of mild acne in the control group. Conclusions: Family history, body mass index, and diet may influence the risk of moderate to severe acne. The influence of environmental and dietetic factors in acne should be further explored. (J Am Acad Dermatol 2012;67:1129-35.)