There are small red dots on the arm like pinpoints which are painless and itchy, and need to be treated according to the etiology. If it is cherry hemangioma, it usually does not need special treatment; for anaphylactic purpura, you can take glucocorticoid medication; for peripheral keratosis pilaris, you can use keratolytic agent. 1. Cherry angioma: the specific etiology is unknown, and the aging of the skin, will increase with age, can be involved in the whole body, often manifested as scattered distribution of corn grain-sized red patches, papules, etc., usually no pain and itching symptoms. There is no pain or itching. This condition does not require special treatment. 2. Allergic purpura: an inflammatory reaction of the blood vessels, which can cause subcutaneous capillary rupture, thus causing skin hemorrhages, skin bruises, which can also lead to small red dots on the arm like a pinpoint without pain or itching. Actively search for causative factors, such as preventing and treating upper respiratory tract infections, getting rid of infected foci (e.g. tonsillitis, dental caries, etc.), and avoiding suspicious drugs. Secondly, rest and topical glucocorticoids are sufficient. In severe cases, glucocorticoids (prednisone) or even combined cytotoxic drugs (cyclophosphamide) should be given systematically. 3. Keratosis pilaris: mostly related to heredity, metabolic disorders and vitamin deficiencies, it will also be manifested as pinpoints of small red flower spots on the arm without pain or itching. In this case, usually no treatment is needed, if there is a requirement for appearance, you can use topical exfoliators such as salicylic acid, adapalene gel and other drugs, but also oral vitamin A and so on. Small red dots on the arms like pinpoints do not hurt or itch, it is recommended to consult a doctor to clarify the cause and follow the doctor’s instructions for treatment. Drugs need to be used in accordance with medical advice.