My husband has a open sore on his buttocks. It started as a pimple,then the head of it turned black . Deep red surrounding it .now it is open sore approx . Pencil eraser in size and extremely tender to the touch. I've been applying prid all natural drawing salve on with bandage, but think now it is open sore, it needs air. At the same time of the onset, he also got approx. a dozen hives and three styles on left eye. He is allergic to salsa and his sister had just givin him a stool softener(prescription)white and red(p10) Any thoughts on the sore or coralation of any of this info put together. Much appreciated sincerely, Cyndie