One of the boys is sick....falling asleep on his feet

Good evening everyone,

I have a sick roo on my hands.  I noticed him this afternoon as I went to collect eggs, he was sleeping on the roost in the coop.  I found it odd but I went on with my chores.  I threw out some treats and he joined in the crowd but I noticed he was falling asleep on his feet.  He would catch himself before falling down but out in the sunshine I could see he was all puffed up and lethargic. 

a few minutes later back in the coop he fell asleep right in the food dish, woke up and went to drink some water and then fell asleep in the middle of the floor.  So I scooped him up and put him in a cage seperate from the rest. 

He is an 8 month old Welsummer. He weighs a bout 9 pounds, feathers are shiney.  He did get a bad case of frost bite and I noticed his comb is really looking yucky.. it doest look infected, but I guess with him falling asleep so much the girls started to peck at it and its a bit bloody.  It is scabbed over on most parts.  I did notice some white areas but its dry not infected.

He has no other injuries other than his comb, when it gets a bit darker I am going to attempt to blue cote it.  I have given him water with vitamins and electro lights in it and he is drinking and eating at this point.

Any ideas on what he may have??? Should I give him some antibiotics???

He is away safe and warm right now and sleeping quietly, away from the others... hoping for the best in the morning

yes he has been checked for mites... nothing... and yes he was de wormed a while back....none of the other chickens are exibiting this behavior... I am wondering if it has to do with his comb.. maybe an infection that is not presenting itself???