My Grand Ma Have Very Big Ulcer On Her Thumb

My Grand ma have very big Ulcer on her thumb for a month now, at first it start slowly with pain the gor big it have become so big with Inflammation and pain her so much, she went to hospital and they gave her antibiotic but up to nw is getting worse, and the thumb is bleeding pls what cn I use to help her in order the Ulcer to get dry??.