For the last month, my 8 year old son has had a fever for 18 days. His fever lasted 8 days, subsided for 5, came back for 5, subsided for 3, came back for 4, and has now subsided for 3! Along with fever, he has NO other symptoms, just a general feeling of being tired or feeling bad. All blood work has come back normal except a sed rate of 99! He has been tested for arthritis , lupus , mono, flu , Kawasaki, etc. What could cause recurrent fever and high sed rate? We are being sent to St. Jude and are very scared!