Small red spots on the body may be allergic dermatitis, early psoriasis, pityriasis rosea or spider nevus and other diseases. 1. Allergic dermatitis: redness, swelling, itching and red spots appear on the surface of the skin after the patient comes into contact with animal proteins or certain chemical substances. Symptoms will be gradually reduced after the patient is detached from the allergen. 2. Early psoriasis: Early psoriasis patients will have red spots on the surface of the skin with white flakes as its typical clinical manifestations. 3. pityriasis rosea: this disease is mostly seen in spring and fall seasons, the cause of the disease is not clear; research believes that this disease is related to viral infection, the patient’s skin surface will appear red spots, which can be self-limiting. 4. Spider nevus: red spots appear on the surface of the patient’s skin, radiating filamentous capillaries in all directions with the spots as the center. This symptom is mostly seen in patients with liver disease, but also in women with high estrogen level. Small red spots on the skin are mostly pathological phenomena, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.