Children with red spots on the arm may be allergic dermatitis, eczema, you can use antihistamines; if it is anaphylactic purpura, you can take glucocorticoid drugs, as well as drugs to improve vascular permeability. 1. Allergic dermatitis, eczema: dermatitis and eczema caused by various reasons may cause red spots on children’s arms, and antihistamines such as cetirizine and chlorpheniramine maleate can be taken, as well as topical glycerine lotion. 2. Anaphylactic purpura: is a vascular inflammatory reaction, can cause subcutaneous capillary rupture, resulting in children’s arms with red spots, you can take prednisone, dexamethasone and other glucocorticosteroid drugs, anti-inflammatory and anti-allergic effect; and vitamin C, rutin tablets and other drugs, to improve vascular permeability. There are many other causes of red spots on children’s arms, it is recommended that parents bring to the hospital in a timely manner to clarify the cause, and standardized treatment by the doctor, do not blindly deal with their own.