Small pimples on the palms of the hands may be caused by mosquito bites, blistering tinea cruris, herpes sweating and other factors. 1. Mosquito bites: If the palm of the hand is bitten by mosquitoes and insects, it may produce local irritation, which will appear in the palm of the hand area of the skin damage such as pimples and wind bumps. 2. Blistering tinea versicolor: generally caused by fungal infections in the hands, which are prevalent in the palms of the hands and between the fingers. In case of blistering tinea versicolor, pinpoint-sized blisters usually appear in the early stage, and if it continues to develop, it may lead to larger blisters. 3. Sweat herpes: it occurs in the palm of the hand, fingers, feet, toes, its typical symptoms for the skin deep in the small blisters, blisters are usually the size of rice grains, can be symmetrical distribution. It is recommended that patients usually pay attention to hand hygiene, avoid scratching, if the symptoms have not been relieved, should promptly go to the hospital, standardized treatment, so as not to delay the condition.