New Developments in Acne and Rosacea Pathogenesis, Treatment, and Comorbidities

Conclusions

• Acne appears to be driven less by the total amount of Cutibacterium acnes and more by shifts toward more virulent, less diverse strains.
• C. acnes biofilm formation likely helps acne lesions form and persist by promoting follicular adhesion and protecting bacteria from host defenses and antibiotics.
• Benzoyl peroxide remains an important acne therapy because it treats lesions without inducing resistance and helps prevent antibiotic-resistant C. acnes when combined with antibiotics.
• Antibiotic monotherapy, especially clindamycin alone, is more likely to select for resistant C. acnes than clindamycin combined with benzoyl peroxide.
• Inflammation seems to begin before visible microcomedone formation, so acne should be viewed as an inflammatory disease from its earliest stages.
• Even comedones, pink macules, and other post-acne marks may reflect ongoing inflammation and still warrant active treatment to reduce scarring risk.
• The early acne lesion may be initiated by an abnormal stem-cell “switch” toward keratinocyte production and sebaceous gland atrophy, potentially triggered by inflammation, hormones, or C. acnes.
• Targeting sebum production offers a promising new acne strategy because it may influence inflammation, keratinization, and bacterial proliferation at the same time.
• Denifanstat, an oral fatty acid synthase inhibitor, showed encouraging efficacy for moderate-to-severe acne with manageable side effects such as dry skin and dry eye.
• An acne vaccine is no longer purely theoretical, as early-phase mRNA vaccine studies are underway and may eventually offer prevention for high-risk patients.
• Rosacea should be considered a condition with meaningful systemic comorbidity, not just a skin-limited facial disorder.
• The meta-analysis suggests rosacea is associated with several gastrointestinal disorders, especially SIBO, IBS, celiac disease, and H. pylori infection.
• Overall, acne and rosacea research is moving toward microbiome-based, anti-inflammatory, sebum-targeting, and preventive approaches that may expand treatment options in the near future.