Red dots on the surface of the skin and an itchy feeling may be allergic dermatitis, papular urticaria and other diseases. 1. Allergic dermatitis is mainly seen as a kind of allergic reaction induced by medicines, food and substances that come into close contact with the skin, and can be manifested in the clinic as a reddish dotted rash, erythema and itchiness that appear all over the body. 2. Papular urticaria, also known as insect bite dermatitis, is an allergic reaction induced by mosquito bites, mainly manifested as scattered distribution of small red dots or small pimples accompanied by itching and pain discomfort. For the red dots with itching, it is recommended to go to the dermatology department of the regular hospital in a timely manner, under the guidance of the doctor for symptomatic treatment.