Multifactorial etiology – ↑ sebum/androgen production, abnormal keratinocyte desquamation, Cutibacterium (formerly Propionibacterium) acnes colonization of the pilosebaceous unit (comedones), and inflammation (papules/pustules, nodules, cysts).

Risk factors:- Increased circulating androgens (eg, puberty, polycystic ovary syndrome)- Mechanical trauma/friction (eg, excessive scrubbing, tight clothing)- Comedonogenic oil-based skin & hair products- Excessive heat- Obesity

Treatment includes retinoids, benzoyl peroxide, and antibiotics.