The causes of red dots on the skin include allergic skin diseases, mosquito bites, cherry-like hemangiomas and so on. 1. Allergic skin diseases: eczema, contact dermatitis and other allergic skin diseases can be manifested as red dots on the skin, symptoms appear after contact with allergens, usually accompanied by other symptoms, such as itchy skin, pimples, maculopapular rashes and so on. 2. Mosquito bites: more mosquitoes in summer and fall, if the skin appears red spots, intense itching, and red spots quickly disappear, may be due to mosquito bites after the body produces allergic reactions. 3. Cherry angioma: the etiology is not very clear, considering the aging of the skin has a certain relationship, can be manifested as the size of the round or ovoid red dots on the skin. There may also be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.