Adult Female Acne: Recent Advances in Pathophysiology and Therapeutic Approaches

Adult acne is a chronic inflammatory disease of the pilosebaceous unit characterized by the excessive production of abnormal sebum favoring an imbalance of the skin microbiota and the hyperproliferation of Cutibacterium acnes and other virulent microbial strains, leading to an inflammatory environment, innate immunity overactivation, and keratinocyte hyperproliferation in hair follicles pores. Degraded keratinocytes plug the pores, consequently forming microcomedons, which can later evolve to papules, nodules, pustules and scars. Distinct from juvenile acne, in adult female acne (AFA) the symptomatology occurs or persists in postadolescence (after age 25). Although hyperandrogenism or the excessive sensitivity of androgen receptors are the main causes, AFA can be triggered by multiple factors, either including or not including androgen disturbances. The prevalence in adult women is 15–20%. Hyperandrogenism is present in 50% of cases; 70% of hyperandrogenism cases feature polycystic ovary syndrome (PCOS), a complex endocrine and metabolic condition. Genetic susceptibility occurs in 80% of acne cases, often with familial inheritance. Beyond classical stepwise therapeutic protocols (topical agents, isotretinoin, antibiotics, hormonal therapy with estrogens, progestins, spironolactone), novel approaches include the highly effective topical antiandrogen clascoterone, the management of insulin resistance by diet, exercise, stress avoidance, and adjuvant therapies such as berberine. Vaccines against the pathogenic proinflammatory C. acnes hyaluronidase A are in development.