Acne incidence in preadolescents and association with increased body mass index: A population-based retrospective cohort study of 643 cases with age- and sex-matched community controls.

Acne incidence is higher in preadolescent girls than boys and increases with age. Preadolescents with acne are more likely to be obese than those without acne. Those with higher BMIs are more likely to be given systemic treatment.