The appearance of small red dots on the skin may be caused by human papilloma virus infection, allergy, cherry angioma and other diseases, and the tests done for different diseases are different. 1. Human papilloma virus infection: you need to go to the hospital for dermoscopy, histopathology test and human papilloma virus test, mainly to check whether you have suffered from human papilloma virus infection. 2. Allergy: If you have mistakenly eaten or touched certain food or articles, in case of allergy, you can go to the hospital to do allergen test through allergen skin prick test or immune stress method to clarify the cause of allergy. 3. Cherry angioma: the outward appearance of this disease is more similar to spider nevus and pigmented purpura skin disease, in case of not being able to clarify the disease, it is recommended to do dermoscopy and histopathological examination. There are many reasons for the appearance of small red spots on the skin, it is recommended to go to the hospital, to clarify the cause of the disease, and follow the doctor’s instructions to standardize the treatment.