Chickenpox is usually most severe 1-2 days after the onset of symptoms, during which a high fever and rash can occur. Chickenpox is a contagious disease caused by varicella-zoster virus and has a certain pattern of onset. It usually begins to appear 1-2 days after infection with a blistering rash, accompanied by chills, fever, headache, fatigue, sore throat, cough, and even gastrointestinal symptoms such as nausea and vomiting. At this time, the symptoms develop more rapidly, and the blistering rash can be distributed on the trunk, head, face or limbs, and the symptoms are most obvious during this period, and the systemic symptoms are also more obvious and relatively severe. Usually 2-4 days later the patient can appear scabs at the same time, fever gradually improved, 1 week after the scabs began to heal and fall off, generally about 10 days to heal. Chickenpox is a contagious disease, the disease should be treated in isolation, more rest, more water, light diet, serious cases may involve internal organs, so it is necessary to actively carry out treatment to avoid aggravation of the disease.