Just dab them with mild iodine and it will help dry them up. Not much else to do except always give them extra vitamins when they are under a stress like that. Are you sure it's pox and not just peck marks with dried blood?
I gather it goes away on its own, when conditions dry up, primarily. If the whole entire flock has it, might need to do something, but when contained I am told one should just let it pass, with no bad effects to be had.