Supplementary Material for: Epidemiology of Acne Vulgaris in 18-Year-Old Male Army Conscripts in a South Brazilian City

Background: Prevalence of acne varies worldwide. Several factors (age, skin color, body fat, diet, and smoking) have been investigated as risk factors. Objective: A total of 2,201 18-year-old males living in Pelotas, South Brazil, were evaluated in order to examine the prevalence of acne and associated factors. Methods: A cross-sectional population-based study was conducted. A dermatologist performed the clinical examination of the face and trunk for identification of acne lesions. Acne was evaluated as clinically noninflammatory, inflammatory, and acne with both types of lesions. Skin color, schooling, height, smoking, skinfolds, waist circumference, BMI, and dietary dairy intake were the independent variables used. Results: A response rate of 97.2% was obtained. Individuals without any acne lesion were 241 (10.9%); 161 (7.3%) only had noninflammatory lesions, 404 (18.4%) only inflammatory lesions; and 1,395 (63.4%) presented both types of lesions. In multivariate analysis, the type of lesions was different in light and dark skin phototype adolescents, with more common inflammatory lesions in the light phototype and noninflammatory ones in the dark phototype patients. Height was directly associated with the occurrence of all types of acne, whereas lower fat mass was associated with the occurrence of noninflammatory acne. While daily consumption of whole milk or yogurt was found to be associated with inflammatory acne in crude analysis, the association with milk was not detected and that with yogurt was low in multivariate analysis. Conclusion: Our results suggest that future studies should explore determinants of noninflammatory and inflammatory acne separately, especially if mixed populations are studied.