Objective To investigate the high-risk factors of premenstrual acne to provide evidence for disease prevention and treatment.MethodsA total of 660 patients with premenstrual acne during February 2006 and October 2009 were retrospectively reviewed.Pillshbury method was used for diagnose and classification of premenstrual acne.Six hundred and sixty complete questionnaires were received for statistic analysis.Results Age and season showed no effect on moderate to sever premenstrual acne.However,spicy and fried food(x2=5.68),mental stress(x2=14.58),gastrointestinal disorders(x2=8.07),family history(x2=12.79),longer hairs around areolas(X2=11.88),and thyroid gland,adrenal gland or adnexal cysts(x2=9.72)had significantimpact on moderate to severpremenstrual acne(all P＜0.05).In addition.inflammatory papules on frontal partress were found in 67.4% of moderate premenstmal acne.ConclusionFood intake,mental health,gastrointestinal disorders,family history,longer hair around areolas,and thyroid gland,adrenal gland,adnexal cysts may be high-risk factors of premenstrual acne.