Hello. Thanks for asking on Healthcaremagic. I am a pathologist and deal with swollen lymph nodes in my patients daily. From your description it seems that the lymph nodes are small less than 1cm and soft and mobile. Usually most common causes are reactive lymphadenitis. In this case any infection in the area of drainage of the lymph nodes will lead to antigen being trapped in the nodes causing an immune response leading to enlargement. Usually it is not of any concern and subsides on its own. Causes could be as simple as dental caries, tonsillitis or pharyngitis, ear infections etc. Sometimes cause of reactive lymphadenitis is not found. Other causes could be a serious chest infection which is ruled out by x Ray in your case. Other rare causes could be a lymphoma or cancer in which lymph nodes are larger and harder in size and not mobile. All these diagnoses can be easily made with a fine needle aspiration cytology test in which a pathologist inserts a needle into the swelling and obtains few cells to be stained and seen under a microscope. However children might find the procedure scary and a bit painful and representative material might not come in small swellings in children. So I suggest you to wait for some time and if it doesn t resolve or grows in size then do a fine needle procedure. Thanks.