1. HEREDITY: Not all patients' parents, of course, can remember acne in their earlier days, but heredity often plays a strong role.

2. STRESS: Nervous tension, pressure, final exams, or a new job can often contribute to a worsening of acne.

3. HORMONES: Hormonal changes at puberty, either in males or females, can cause an outbreak of acne. In women, the monthly cycle, pregnancy, birth control pills, or menopause are often contributing factors.

4. BACTERIA: Skin bacteria plays a prominent role in acne. For this reason, oral or topical antibiotics are commonly used for therapy.

5. COSMETICS: No brands in the market (save one) are completely free of comedogenic or potentially irritating ingredients (The Regine Line at www.dermalinellc.com is the only line with all ingredients rated "0" on a master list of comedogenicity and irritancy).