My 5 years old son has experienced severe pain in his muscles The pain is so much that he is not able to walk. This pain generally has occurred after 3-5 days of fever .When his CPK levels were checked through blood samples, they were extremely high . CPK levels went upto 2480.The child is otherwise very very healthy and active. really really worried for my child...Please Guide and HELP how do I get clarity on this. Are there any further investigations to be done?????