We are taking the jacket off a couple times a week to let the skin air out and so that she can clean herself naturally, but this one spot is horrendous. There is some hydrocortisone on the area, and she was licking herself as I was snappjng these.
My cat had something similar and it turned out she was allergic to fleas. She didn't even actually had fleas, just gotten bitten by a couple from neighbor cats and it took weeks to make it less itchy. A cortisone shot of like 15 bucks was all she needed. And regular flea drops.