Red dots on the legs may be caused by spider nevus, purpura and contact dermatitis, etc. Different treatments can be used depending on the cause of the disease. 1. Spider nevus: If spider nevus causes small red spots on the legs, wear loose and comfortable pants and do not scratch the affected area. Patients can take high-frequency electrocautery, carbon dioxide laser and other methods as prescribed by doctors to destroy the central blood vessels, so as to achieve the therapeutic purpose. 2. Anaphylactic purpura: small red spots on the legs may be caused by anaphylactic purpura, daily need to rest in bed, looking for allergens, avoid re-exposure. Patients can take antihistamines such as loratadine and chlorpheniramine as prescribed by the doctor, which have anti-allergic effects. 3. Contact dermatitis: small red spots on the legs may be caused by contact dermatitis, daily need to avoid contact with allergens. Patients can follow the doctor’s instructions for topical glucocorticoids, such as hydrocortisone, dexamethasone, etc., to play an anti-allergic role. There are many causes of small red spots on the legs, it is recommended that patients go to the hospital, under the guidance of the doctor standardized treatment.