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.
Definitely see a vet.
Things that can help (but not remediate): Keep the water bowl full and add a second if it ever empties, just to ensure access. Keep stress low.