Red bumps on the waist may be suffering from contact dermatitis, urticaria or viral herpes, etc. It is recommended to consult a dermatologist for treatment. 1. Contact dermatitis: refers to the direct contact of human skin with certain substances, resulting in skin inflammation, limited, can be accompanied by intense itching symptoms. The causes are categorized as allergy (allergic contact dermatitis) or external irritation (irritant contact dermatitis). 2. Urticaria: commonly known as hives or rubella, is a kind of skin allergy. It is a skin allergy that is characterized by localized redness, swelling and itching of the skin. Hives usually appear after infections, food and drug allergies, or insect bites; in addition, stress and sleep deprivation may trigger it. 3. Viral herpes: Viral herpes is a viral skin disease caused by the viral herpes virus. It is commonly found in areas innervated by the intercostal nerve, cervical nerve, trigeminal nerve and lumbosacral nerve, such as the face, neck, chest and back, waist and abdomen, and will be accompanied by neuralgia before or at the time of rash, and is prone to recurrence. Red bumps on the waist may also be other reasons, it is recommended that the patient to the hospital in time, after clarifying the cause of the disease, standardized treatment under the guidance of the doctor.