Question from Phoenix, Arizona, USA:

I took my son to the Emergency Room yesterday because he had abdominal pain that became severe when he tried to walk. He had fevers from 99.5 to 103.5 degrees F. He was tired and had little appetite. The pain in the lower abdomen is worse on the right. They did blood tests and think he has mononucleosis. Tests were inconclusive and should be repeated in about a week. His pain is still severe when he moves and is getting worse, even with rest. I have looked up mononucleosis and just don’t see this type of pain usually associated with it. They did say his inguinal lymph nodes were swollen. I am concerned. I think something else is wrong. He is in too much pain and has no energy. Just this morning, he complained of joint pain in his ankles and knees. They have him on generic Vicodin, as needed.