Red dots on the skin after fever are considered to be viral rash caused by viral infection or scarlet fever caused by bacterial infection. It is considered to be an allergic rash caused by hot and cold stimulation of bacteria, viral infection, and drug allergy after fever. The viral rash has no conscious symptoms, the rash is uniform in size and shape, mostly appears first on the head and face with fever and head discomfort, and is treated symptomatically, with a duration of 7-14 days. In case of scarlet fever, bacterial infection is considered, mostly accompanied by tonsillitis and prune tongue, which requires timely antibiotic treatment. In case of allergic rash, it can be accompanied by itching, and the rash can be polymorphic, reddish in color, with the trunk appearing first, treatment requires removing the allergen, actively controlling the infection, giving anti-allergy medication, and in severe cases, glucocorticoid treatment.