Hello and thanks for sending the question. The most likely contributing factor to lymph node swelling such as that which you describe is some type of viral illness or possibly allergic reaction. This type of reaction will usually last a few days or possibly a few weeks. As long as the white blood cell count hemoglobin and platelets are within normal limits this is more reassuring. At the same time this needs to be monitored closely. If the swelling continues then a biopsy might be recommended. Where causes of this type of reaction would include some type of childhood lymphoma. I think this is not likely but it must be considered and rolled out. Thanks again for sending your question. Dr. Galamaga