A small red spot on the waistline is considered to be caused by herpes zoster, contact dermatitis and eczema. 1. herpes zoster: herpes zoster is due to chickenpox – herpes zoster virus caused by infectious diseases, usually in the immune system is relatively easy to develop, in the early stages of the disease will be manifested as erythema, pimples and other lesions phenomenon, with the development of the disease may appear pimples and blisters, accompanied by neuralgia. 2. Contact dermatitis: if the patient belongs to the allergic body, waist around the long time contact with chemical fiber, cashmere or the metal part of the belt, it is easy to produce an allergic reaction, thus causing contact dermatitis, pimples, erythema, swelling, blisters and other lesions, accompanied by itching. 3. Eczema: Eczema is a chronic inflammatory itchy skin disease, the pathogenesis is not clear, but usually considered with genetic, immune abnormalities, hormone level changes and endocrine diseases and other factors, usually manifested as papules, papules, erythema, blisters and other lesions, accompanied by obvious itching, with the development of the disease will also be red, swollen, flaky. As the cause of a small red spots around the waist for a variety of reasons, so when patients appear related symptoms, it is recommended to go to the hospital in a timely manner to check and diagnose the cause of the disease in the guidance of a professional doctor for targeted treatment, to avoid misunderstanding the condition aggravate the symptoms.