What IS this? A blister?

[Zewlie]

I was out checking the chickens this morning when I noticed that one of my 8-week-old cochins was hiding a bald spot around her shoulder. I picked her up and, to my surprise, found what looks like a MASSIVE blister. The skin feels thin, there are only a few pin feathers on it, and veins are visible. An extreme close-up:



Any idea on what I should do about this? Do I just leave it? Drain it?

 

[Rebecca in FL]

Any ideas .... or responses on what that was? I have a Polish 4 week old with almost the same thing, blister like thing on the shoulder - feathers missing. I dusted last night with garden dust, today I put a drop of Vet RX on it. The grainy things weren't there yesterday, and I think its food ..... the blister does seem smaller in size today.

 

[Rebecca in FL]

This is my chick with the same problem: