While acne is commonly associated with adolescence, it may persist well into adulthood. Acne typically manifests around the age of 11, peaking at about the age of 16. However some people will experience acne continually in their 20s to 50s1,2. What cause adult acne? As in adolescent acne, what causes acne in adults starts with the pores of the skin becoming clogged by excess oil production, dead skin cells, and bacteria3. Adult onset acne is more commonly related to underlying issues of hormonal imbalance.