Small red dots on the hands are painless and itchy, considering that they are related to thrombocytopenic purpura, keratosis pilaris, syphilis, and so on. 1. Thrombocytopenic purpura: Thrombocytopenic purpura can cause petechiae and ecchymoses on the skin and mucous membranes of patients, and small red dots on the hands that are painless and itchy can also appear. The cause of Thrombocytopenic Purpura is still unclear, it may be related to human immune system disorders, some patients may also be accompanied by nasal cavity, gum bleeding, and even intracranial hemorrhage. 2. Follicular keratosis: Follicular keratosis is an autosomal dominant disease, in addition to genetic factors, but also with hormone level changes, immune system abnormalities and so on. Disease will cause the patient local skin pinpoint to pea size, hard papules, so it can be manifested as a hand long small red dots do not hurt and itchy. 3. Syphilis: the second stage of syphilis rash can be manifested as small red dots on the hands of some patients and painless and itchy. Syphilis is caused by the infection of the pallid spirochete, which often causes the patient to develop a hard chancre, enlarged lymph nodes, and a syphilis rash (red or reddish-brown pimples), etc. It is recommended that the small red dots on the hands be painless and itchy. It is recommended that people with small red dots on their hands that do not hurt or itch should consult a doctor for a clear diagnosis of the disease and then follow the doctor’s instructions for treatment.