High blood sugar causes itchy skin, consider diabetes caused by diabetic skin disease, in this case need to use insulin to control blood sugar. At the same time, we need to combine the consultation opinion of the dermatology department to see whether it is just simple allergy or there is eczema, if it is allergy, you need to take anti-allergy medicine, if it is eczema, you need to take medicine for eczema, so it needs to be treated by both departments together. After blood sugar is controlled and skin itching is fully recovered, with the recovery of pancreatic islet function, oral hypoglycemic drugs will be changed according to the situation, but when blood sugar is high and accompanied by skin itching, insulin must be used to control blood sugar and keep fasting blood sugar below 7.0 mmol/L and postprandial above 7.8 mmol/L. Generally, in about two weeks, the itchy skin can be completely restored to normal, while one still needs to avoid eating.