Talk to Pediatrician on White Spots Inner Cheeks

Hello. I need your help. I have a 1 year old boy with some white spots that appeared about 2 weeks ago, just in the inner cheeks, at both sides. It doesn't bother him. I applied some solution with nystatin more than 10 days, and than the dr gave me some cream with fluconazol. I don't see any improvement. He never had such a thing in is mouth. P. S He gets ill often, (flu) from his brother who goes to help me! Thank you, Adele