I. Skin: Observe the rash form, number and location, and whether it recurs. If the rash is itchy, keep the skin clean, prevent abrasions and scratches, and treat any breakouts promptly to prevent bleeding and infection. Remove any allergens that may be present. Use hemostatic drugs and desensitizing drugs as prescribed by the doctor. Joint swelling and pain: Observe the pain and swelling in joint type cases, maintain the functional position of the affected limb, assist the child to choose a comfortable position, apply cold or hot compresses according to the condition, and do the daily care. Abdominal pain: Try to rest in bed and guard the bedside as much as possible. Observe whether there is abdominal colic, vomiting and bloody stools. Pay attention to the nature of the stool, sometimes the appearance of normal but positive occult blood. If there is blood in the stool, record the number of stools and their properties in detail, and keep stool specimens. Abdominal pain is forbidden to apply heat to the abdomen to prevent intestinal bleeding. Fourth, nephritis: observe changes in urine volume, urine color, urine shape and urine quality density, do regular urine examination, and record the amount of in and out according to medical advice.