How long it takes for lymph nodes to subside in a 3 year old child is the main determination of the primary disease of the enlarged lymph nodes. Inflammation of the lymph nodes can subside in about 1~2 weeks after reasonable use of antibiotics. Most of the causes of lymph node enlargement in children are related to inflammation, after the occurrence of bacterial infection or viral infection, causing lymph node reactive enlargement, you need to actively treat the primary disease under the guidance of the doctor, the lymph node enlargement can disappear. If the lymph node enlargement is larger than one centimeter in diameter, and there is obvious pain when pressed, you can use antibiotics appropriately under the guidance of the doctor to carry out treatment, antibiotics can choose penicillin antibiotics or cephalosporin antibiotics, and surgical incision is needed to treat the formation of abscesses. When the inflammation of lymph nodes in children does not get better, it is necessary to determine whether there is the possibility of tuberculosis or lymphoma, and it is recommended to consult the general surgery department of regular hospitals.