Acne in the lower abdominal triangle may be caused by vulvar folliculitis, vulvar eczema, warts and other diseases. 1. Vulvar folliculitis: Vulvar folliculitis is an inflammation of the skin caused by bacterial infection, and the hair follicles in the area of the patient’s lower abdominal triangle are susceptible to inflammatory infections, resulting in acne and painful symptoms. 2. Vulvar eczema: Vulvar eczema is an inflammatory skin disease of the vulva caused by a variety of factors, and when you suffer from vulvar eczema, you are prone to the symptoms of acne in the lower abdominal triangle. 3. Condyloma acuminatum: Condyloma acuminatum is a skin disease caused by human papilloma virus infection, which can easily cause the skin around the external genitalia or anus, appearing more than one small reddish particles, and also accompanied by local itching symptoms. The appearance of the lower abdominal triangle acne, should promptly go to the hospital, under the guidance of the doctor for formal treatment.