1- Hormonal Activity: Acne development can be enhanced by increased hormonal levels as in puberty period or menstrual cycle. 2- Psychological Factors: Increased stress level may contribute in acne formation according to recent studies. 3- Genetic Factors: Family history of acne is a risk factor for acne formation especially in adolescent. 4- Infections: Some types of bacteria causes acne formation 5- Drugs: Certain drugs can stimulate acne formation as