Red dots on the back may be caused by folliculitis, eczema, cherry angioma and other diseases. 1. Folliculitis: an infectious disease caused by fungal or bacterial infection of the hair follicles, poor hygiene, low immunity can trigger the disease, clinically manifested as follicular papules, pustules, accompanied by itching, tenderness and other symptoms. There will also be red dots on the back. 2. Eczema: the cause of the disease is not clear, may be related to genetic, immune abnormalities and other factors. Patients will have localized erythema, papules, blisters and other symptoms, which can be distributed in any location of the body. 3. Cherry angioma: the cause can be related to aging, gene mutation and other factors. Patients will have localized pimples or nodules, which are bright red or purplish red in color, with a diameter of 1~5mm, mostly seen in trunk and upper limbs, and generally without conscious symptoms. There are more causes of red dots on the back, it is recommended to go to a regular hospital for examination to clarify the cause of the disease.