Four and a half year old boy with a runny nose and cough and low fever, may be bacterial infection or allergies, etc., in the treatment of the main drugs, while with the daily home care and so on. 1. pus runny nose: boys if pus runny nose and bacterial infection, need to use the relevant antibiotics for treatment, such as cefixime, amoxicillin and other drugs. 2. Cough: If the symptoms are caused by allergic cough, you need to take loratadine, cetirizine and other drugs; if the cough is caused by a cold, you need to take some drugs for the treatment of colds, such as pediatric aminophenol xuanamin granules and so on. 3. low fever: boys have a low fever, usually not more than 38.5 degrees, can not take fever-reducing drugs, give priority to physical cooling, with a towel to wipe the palms of the hands, feet, and armpits and other parts of the body, at the same time with the above medication is more effective. The four-and-a-half-year-old boy with a pus-filled nose and cough and low fever may also have other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, to give targeted treatment or treatment. All of the above drugs are taken under the guidance of a doctor.