I started to get that itching on my mid upper back and arms and almost 9 months ago now. I thought it was eczema. I went to one dermatologist and she ened up a freezing a few spots. She said it had to do with my nerves? It was a medically complicated explanation. So I went to another dermatologist for a second opinion (always do that and research it for yourself!).
At the end of the day, it ended up being contact hives, more specifically, see below.
Chronic idiopathic urticaria (CIU) is the persistent, often daily appearance of hives (urticaria) that last for six or more weeks for no known reason. These hives are often itchy welts or bumps that appear when a trigger in the body causes mast cells to release histamine, serotonin, or other chemicals under the skin (which they are finding out is related to long Covid).
I had already been on Dupixent, which both dermatologist said that if I hadn't, that the hives would have been worse. The second dermatologist put me on the Xolair, but before the third injection, I ended up itching worse than before and stopped using it. Right now, I just continue my Dupixent injections (2x a month), use my over the counter FexofenadineHydochloride (allergy relief-two times a day), and my Triamcinolone Acetonide cream (as needed). I traded out my body wash for some Aveeno body wash that is fragrance free and try to keep my skin moisturized. If you have animals, keep your bed sheets clean as often as you can too.
This has at least kept my itching managable. I hope this helps someone out there. I'm actually going to see a third Dermatologist this week, I don't give up that easily to try and figure things out. I've been doing a lot of research on my own and hoping to figure something out. Keep you all posted.