Red bumps on the body may be caused by atopic dermatitis, papular urticaria, hives and other diseases. 1. Atopic dermatitis: it is a common chronic, recurrent, inflammatory skin disease with a complex etiology that may be related to genetics, immune abnormalities, environmental factors, and abnormal skin barrier function. There are symptoms such as dry skin, pimples, papules, and intense itching, thus manifesting as red bumps on the body. 2. Papular urticaria: an allergic skin disease that occurs after insect bites, a fusiform, windswept papule with blisters at the top, occurring in exposed areas of the skin or clothing openings. Thus, there is the manifestation of red bumps on the body. 3. Urticaria: It is an edematous mass confined to the surface of the skin and mucous membranes, and the causes include physical stimuli, food, drugs, and infections. If you suffer from urticaria, red bumps will appear on the patient’s body. There are many causes of red bumps on the body, and it is recommended that patients go to the hospital in time to clarify the cause of the disease.