Suggest Treatment For Child Having Red Itchy Bumps On Ears And Cheeks

My 5 year old son has red raised little bumps on his ears and a few scattered on his cheeks. He also has raised bumps scattered all over his body, but not red. He says he s itchy so I ve been giving him Benadryl. I m wondering if it could be an allergic reaction or a viral rash... Does he need to see his pediatrician?