My 4 month old has a bad yeast infection under his neck. Its going to be 2 weeks Friday since we've been to the pediatrician and she gave us nystatin to treat it. Although he's had it for awhile and she told me it was just dry patches and gave me vanicream to put on it but it wont go away and its spreading to his chest and his jaw and cheeks. He's been scratching it and I clean his hands but I don't know how its spreading. I change his bibs frequently during the day and he sleeps naked at night. I don't know what to do for my poor baby. What should I do?