Background: Acne is a common disease in adolescents, but there are no epidemiological data for acne in Brazil.
Objectives: To estimate the prevalence and degree of acne in adolescents from Sao Paulo and study socio-demographic factors, family history and lifestyle, associated with the disease.
Methods: Cross-sectional study with 452 adolescents aged between 10 and 17 (mean=13.3 years), students from elementary and high school, examined by 3 independent evaluators.
Results: 62.4% were female, 85.8% white and 6.4% were aged 14. The prevalence was 96.0% and increased with age--all students over 14 had acne. The most prevalent form of acne was comedonal (61.1%), followed by mild (30.6%) and moderate (7.6%) papular-pustular, which affected mostly the face (97.5%). About half of the adolescents reported family history for acne in mother or father, and 20.6% reported previous treatment for acne. There was a higher chance of presenting non-comedonal acne with increased age (p<0.001).
Discussion: The prevalence of acne in adolescents varies widely due to the clinical features and diagnostic methods used. Adolescents whose brothers/sisters had acne (OR=1.7-p=0.027) and those over 13 (OR=8.3-p<0.001), were more likely to have non-comedonal acne.
Conclusion: This study showed high prevalence of acne in adolescents from Sao Paulo, predominantly the comedonal form on the face, with a higher chance of presenting non-comedonal acne with increased age.