Acne on the belly may be caused by folliculitis, ringworm and other diseases. 1. Folliculitis: it is an inflammatory skin disease mainly involving hair follicles, and the cause of the disease is related to bacteria, fungi, viruses and so on. Patients will appear localized red papules, pustules and other symptoms, may be accompanied by pain. 2. Tinea corporis: it is a fungal infection that occurs in the superficial parts of the skin, the cause of which is related to infection, environment and other factors, and it is mostly seen in the trunk, arms and other parts of the body. Patients will appear localized pimples, blisters, erythema and other symptoms, the affected area is usually accompanied by different degrees of itching. There are many reasons for acne on the belly, and patients are advised to go to a regular hospital for examination to clarify the cause.