The causes of subcutaneous red dots on the back of the hand include viral rash, idiopathic purpura, leukemia, mosquito bites, etc. Treatment includes medication and surgery. 1. Viral rash: If the red dots are caused by viral skin infections that lead to skin damage, interferon antiviral therapy can be given at this time. 2. Idiopathic purpura: For purpura caused by unknown reasons, vitamin C and other medications can be given at this time. 3. Leukemia: If it is leukemia, hydroxyurea, allopurinol and other drugs can be given to treat it, and bone marrow transplantation can be given if necessary. 4. Mosquito bites: If mosquito bites cause small red spots, you need to give glycerin lotion to eliminate itching. The back of the hand appeared subcutaneous red dots without pain and itch may have other reasons, it is recommended to consult a doctor in a timely manner, under the guidance of the doctor’s medication. All of the above medications should be prescribed by a doctor.