Systemic rash refers to the appearance of skin rashes all over the body caused by various reasons. Clinical diseases that can cause generalized rash include urticaria, syphilis, measles, etc. For example, urticaria is caused by contact with allergens such as pollen, dust, cold air, food, etc. leading to an allergic reaction that causes itching of the skin, followed by generalized, irregular red or pale white wind-ball lesions of varying sizes, and most rashes can be eliminated in a short period of time through timely intervention. The types of skin lesions usually include primary and secondary, primary such as macular rash, maculopapular rash, papules, papules, and windmills, etc.; secondary skin lesions are usually scratches, scales, and ulcers based on the primary skin lesions. If there is a generalized rash, you should go to the hospital in a timely manner to seek medical treatment, after clarifying the cause of the disease, so as not to delay the condition.