I'm 11 years old and did the salt and ice chalenge I got pimples and my skin is starting to peel of I got a massive red mark on my arm I did not show this anyone please HELP

Can't help you. You purposely gave yourself frostbite. You will just need to wait it out and hope you aren't scarred for life.

I fear for the future of mankind...

Denis, for future reference, if it has "challenge" in the title it's probably dangerous. Don't do it.

I am going to suggest showing it to your parents to make certain it is healing properly. They can see it and we can't.

They may get upset but part of life and growing up is accepting the consequences when you do something you know you shouldn't have.

Go to your school nurse this morning. Your parents will be called to take you to a doctor, if necessary. Hopefully, you learned a lesson.