Obviously you should consider Hepatitis A, as well as Epstein Barr Virus and Cytomegalovirus which can both give an upper respiratory tract picture with enlarged lymph nodes, liver or spleen. Cholangitis (Virchov s triad of fever pain and jaundice) is also in the differential diagnosis as is a pyogenic live abscess although that is pretty rare. I would certainly focus on supportive care (hydration, oxygen, possibly empirical antibiotics) while organizing an ultrasound of the liver and biliary system. This child sounds sick and should be cared for in a hospital if possible.