Have you treated for mites, lice, and worms? I've had a hen that, unbeknownst to me, had a large infestation of mites and she looked similar to this. She could hardly walk because of how anemic she was and her comb and wattles were very pale.
I just got back from the coop and I found a hell of a lot of mosquetos flying around the hens, I even saw one on the eye area of one of the sick ladies, could this be the reason for the swelling and what I have noticed is these swellings are more like a lumps and there are now 3 ladies that have these swellings but it 's not affecting their eating habits they just not laying like they did......what you think guys ???