If it is fowl pox, the sites I've looked at, like poultrypedia.com say to use tetracycline to prevent secondary infection. I use the Durvet water soluble at 1 teaspoon per gallon or 1/4 teaspoon per quart, and mix fresh daily. It will help with secondary infection. Make the poor little guy some oatmeal or a hard boiled egg so he has something soft to eat, his poor little head must hurt so. Triple antibiotic salve on his sores should help, too. Good luck, I hope he gets well soon.