Itch, itch, ITCH!

Kay, so this is a new one on me. My mastectomy/radiation zone has been itching like crazy since last night. Lotion doesn't seem to stop it, nor do essential oils of lavender, peppermint and Peace and Calm. Why the heck is it itching now? It never has before. In my mind, my mass is shrinking, and all is healing. You know- that itching that comes along with healing. Probably not really the cause, but it works for me in my mind until I find out the real answer!