My son is 4 yrs old and he gets them. I just put diaper cream on them. I let him go without his underwear for a little bit to air out. Call his dr if they don't get better
My daughter had a really weird and horrible rash like that and I took her to the doctor. They had to prescribe two ointments for her that she had to use twice a day along with diaper rash creme and putting the diapers on loose and letting it get air when possible.
You might want to call his pediatrician just to get it looked at in case he needs any special ointments for it
Could just be a regular diaper rash, butif it's not going away it could be a yeast diaper rash. If regular diaper cream doesn't clear it up within a few days, talk to his doctor. You may need a special topical cream (possibly Nystatin cream) if it's a yeast diaper rash. You could try a little cornstarch to keep his bum dry and change his diaper often. Also, keep it clean and give it some time to air dry too.