My 3 1/2 yr old son has been having severe joint pain along with a rash. He gets hives over his joints and everyday is somewhere new. By the end of the day he limps and sometimes can't walk. He has had one purpura rash on his stomach which led the Dr. To test for Mono and it was positive. Small red dots appear all over him with activity. He has seen a rheumatologist but she said all his blood work looked good. It breaks my heart watching him in pain. The everyday pain is in his knees but at night the ankles and back of knee hurts. Even his hand and wrist.