Itchy skin with Keytruda

Hi, I'm going to have my last of 14 immunotherapy infusions for tongue cancer in a few weeks. I'm in a study, and had two infusions, plus 4 radiation treatments, then surgery to remove squamous cell carcinoma from about 1/2 my tongue and 63 lymph nodes from both sides of my neck. They created a graft (flap) from my forearm and an artery. Very good results from all this...got good margins and clear lymph nodes, but it was a wild ride. Then every 3 weeks an infusion of immunotherapy (Keytruda) for most of this past year. Things have gone very well with that (tiredness and itchiness are the main thing I've dealt with). Lately, I'm itching just about all the time. No rash, but itching everywhere, not all at once, but my stomach, then my back, or my arms, or legs...on and on. It's making me crazy. Have any of you found a good answer to this? I'd like to find some kind of a spray, since rubbing cream on my own back would be impossible. Or something oral, but I'd kind of hate to take something that makes me sleepy. Thanks for any suggestions! I can ask my oncology team,but thought I'd run it by you folks, too.
Jennifer