Is this just dry skin?

My 10 year old boxer has been having a hell of a time these last few months. The working theory is that she has IBD.

She’s been eating well, now on a new diet for the IBD, but continues to lose weight. She’s lost about 15 lbs since January.

I noticed this spot in her arm today. The left patch is flaky like dry skin, but the right bit is a bit raised and red around the edges.

https://imgur.com/a/oRDqY6D