Phantom limb syndrome is thought to be caused by the brain adapting to changed signals from the limb's nerves. It means years of pain, itching, false sensation. I can't even begin to imagine what it would take to address phantom body syndrome.
A medication (topomax) once gave me the reverse. My left arm felt like a complete stranger. Was terrified of it. Intellectually I understood it was just the medication screwing with me. Emotionally I wanted to take a chainsaw to that arm.
(I'm also a total layman here)