Red spots on the hands may be due to syphilis rash, sweat herpes, purpura and other causes. 1. Syphilis rash: mainly appear in the second stage of syphilis, manifested as a generalized rash, can occur in the palms of the hands, limbs, face, trunk, feet and other parts of the body, which can be manifested as a red macular rash, papules, scales and so on. 2. Sweat herpes: the etiology and pathogenesis are not clear, may be related to psychiatric factors, infection, local allergies or irritation, patients often first appear intense itching, may be accompanied by burning sensation and tingling and other symptoms, usually in the palms of the hands, fingers and other parts of the body, often symmetrical distribution, may appear pinpoint to rice grain size blisters, red spots. 3. Anaphylactic purpura: small red dots on the hands may be caused by anaphylactic purpura. Allergic purpura is a disease of capillaries and small blood vessels that undergoes metamorphic reaction, which can be caused by bacterial and viral infections, as well as food and drug allergies, etc. Because of the increase in vascular permeability, the red blood cells can seep out into the skin, which is why they are manifested as small red dots. Red dots on the hands may also be other diseases, it is recommended to consult a doctor in time to clarify the diagnosis.