bizarre! the only similar thing I've seen on my whites is when half of them was in the light and they were under cover on the other half.
Does it Yawn a lot? more than would be accounted for by shedding?
Thank you for looking, no he doesn't yawn or act abnormal. I have googled like crazy and can't find anything like it. He had it on the other side before and I just kept an eye on it. Now it switched sides. Its just really strange.