Croup and medicine reactions

My daughter is 2. She came down w an ear infection and croup. The croup was so bad they put her on prednisone which stopped her coughing. Now she woke in the middle of the night because she's so itchy. Her legs won't stop itching. I gave her benedryl in the hopes that it would help stop the itch and it didn't. Has anyone else ever dealt with this? I'm assuming it's a reaction to the prednisone. Any thoughts would be helpful.