I have separated a hen from the rest of the flock. She was staying away from the rest of the flock in a dark corner. The cage utilizes the deep litter method and it did get wet from a heavy thunderstorm. She was living in a wet, dark environment for a few days before I got to clean everything out. The other two hens have shown no signs of anything amiss. The hen in question was getting puffy around her crown and I wondered about Coryza. However after about a week or two of isolation she seems to be doing pretty well and the swelling has gone down. She is eating, drinking and laying well. There was never any discharge in the eyes or nasal cavity, no pink swelling, no trouble breathing or foul smell. Her eyes were clear and healthy looking. There was just a raising of the feathers in her crown area right above the eyes that slightly lifted up her eyelid giving her and 'angry look'. Any ideas on what it could be? Can I put her back with the flock?