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).DISCUSSIONThe 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.

Background Oral isotretinoin (ISO) is the only drug which promotes prolonged remission

Background Topical tretinoin cream is the gold standard treatment for skin ageing, particularly photoaging. The purpose of tretinoin peel was to obtain similar results, but in a shorter time, however, there have been few controlled trials on its effectiveness. Objective To compare efficacy and safety of tretinoin 0.05% cream and 5% as a peeling agent on photoaging and field cancerization of the forearms. Methods Clinical trial with therapeutic intervention, prospective, randomized (computer‐generated randomization list), parallel, comparative (intrasubject) and evaluator‐blinded (except for histology and immunohistochemistry), including 24 women (48 forearms) aged over 60 years who have not undergone hormone replacement and categorized as Fitzpatrick skin phototype II or III. The forearms of the participants were randomized for treatment with 0.05% tretinoin cream three nights a week, or 5% tretinoin peel every 2 weeks. The opinion of the participant, severity of photoaging, corneometry, profilometry, high‐frequency ultrasound, histology (haematoxylin–eosin and Verhoeff stainings) and immunohistochemistry (p53, bcl‐2, Ki67 and collagen I) were assessed. Results One participant dropped out. The mean photoaging score reduced 20% and the mean actinic keratosis (AK) count reduced 60% with no difference between treatments. Three efficacy parameters showed opposite effects between the tretinoin treatments (P < 0.05%): (i) thickness of the corneal layer decreased with 0.05% tretinoin and increased by 5%; (ii) dermis echogenicity increased by 0.05% and decreased by 5% and (iii) Ki67 expression increased by 0.05% and decreased by 5%. There was good tolerability for both regimens. Conclusion Tretinoin as a cream 0.05% or peeling (5%) is safe and effective for the treatment of moderate photoaging and forearm field cancerization. The cream was superior in improving ultrasonographic parameters of ageing. Peeling was shown a superior performance in the stabilization of field cancerization.

The current recommendation to wait 6 to 12 months after treatment with oral isotretinoin for acne scar revision using dermabrasion should be re-evaluated. Abrasion of a small test area may be a useful predictor of wound healing, enabling earlier acne scar treatment using this procedure.

A validated clinical photoaging scale for forearms with internal consistency, reliability, and validity was developed.