Rash diseases, as the name implies, are diseases in which the main clinical manifestation is a skin rash, which can be divided into allergic rashes (drug and food allergies) and infectious rashes (such as measles, chicken pox, scarlet fever, etc.) depending on the cause. Allergic rash is more common in children, often related to drugs, and is sometimes misdiagnosed as “eczema”. The main symptoms are: abdominal pain, crying and restlessness, no vomiting and diarrhea, a flaky rash over the body, above the skin surface, itching and fever. Treatment: First of all, the allergen should be excluded (such as avoiding re-exposure to foods or drugs that may trigger allergy, etc.), anti-allergy drugs (such as promethazine hydrochloride, calcium gluconate, dexamethasone, etc.) are available, and if it is not possible to determine which drug is the case, the drug used should be stopped immediately and replaced with anti-allergy drugs such as hormones. Infectious rashes are mostly caused by viral infections, such as measles, chicken pox, scarlet fever, etc. Among the common infectious diseases in children, these lesions are mostly contagious and may contain corresponding viruses in the rash and blood, so you should avoid scratching the skin when the rash itches to avoid inducing secondary infections in healthy skin. It is difficult to control the rash with antipyretic drugs, so it is important to note that in this type of disease, high fever accompanied by a rash should not be used arbitrarily before the cause of the disease is clear, to prevent the body temperature from dropping suddenly and causing the rash to be impermeable, which increases the difficulty in diagnosing the disease and increases the risk of complications. If the body temperature continues to rise after the rash has developed, the presence of complications such as bronchopneumonia and myocarditis should be considered, and appropriate tests and treatment should be performed. To determine the time relationship between fever and rash in pediatric rash diseases, the clinical summary has the following recipe, I hope to remember: 1, pox (that is, the first day of fever rash, the following diseases involved in this pattern analogous) 2, scarlet (that is, scarlet fever) 3, smallpox 4, measles 7 typhoid and typhus. If the child has a history of suspected infectious disease contact, he or she can go directly to a hospital specializing in infectious diseases to avoid delays due to repeated referrals.