The baby fever after the rash usually have to consider the following situations: First, relatively common, if the fever is 3-5 days after the fever is not fever rash, usually considered for early childhood emergency rash, human herpesvirus 6 infection caused by the rash will not need special treatment, as long as attention is paid to try not to intake of allergy-prone foods can be. Secondly, after the fever rash should also pay attention to the drugs taken whether the drug allergic reaction, if the rash disappears after stopping the drug, and then take the same drug again and the rash should be considered drug allergy, need to take anti-allergy drugs, such as cetirizine hydrochloride or loratadine. Thirdly, some children have a rash after the fever goes down, and after the rash, the fever recurs again, but also pay attention to whether there is measles or other viral or bacterial infections that are not effectively controlled, because bacterial or viral infections can release toxins and cause a rash.