Acne cosmetica revisited: a case-control study shows a dose-dependent inverse association between overall cosmetic use and post-adolescent acne.

BACKGROUND: Case-control studies to support the concept of acne cosmetica are lacking.

OBJECTIVE: To examine the association of post-adolescent acne with the use of cosmetics and cosmetic procedures.

METHODS: 910 post-adolescent patients with acne and an equal number of matched controls were studied for exposure to cosmetics and cosmetic procedures. A cumulative cosmetic exposure index was stratified into four quarters of increasing exposure.

RESULTS: Comparison of different cumulative exposure categories with the lowest exposure category (multivariate analysis, logistic regression) showed that the odds ratios, which were always <1, progressively declined as cosmetic exposure increased [odds ratios (95% confidence intervals): 0.679 (0.501-0.922), 0.355 (0.258-0.487), 0.307 (0.217-0.433)]. However, some individual cosmetics had odds ratios >1.

CONCLUSION: Overall cosmetic use was negatively associated with post-adolescent acne. The term 'acne cosmetica' is appropriate in the sense that some cosmetics may cause acne.