I always feel bad for my kids when they get diaper rash. Sensitive skin, a little red butt, and pain when being wiped. There are a ton of products out there for diaper rash- most of which (as far as I've seen) are all creams. One of the best pieces of advice I ever got from my pediatrician was to NOT use any of those creams or ointments. The problem with them is that they lock moisture in when it was the moisture on the skin causing diaper rash in the first place!
My youngest, the Climber, seems to be the one who has had the worst experience with diaper rash. As the third child, he gets carted around from place to place and probably spends too much time in the same diaper. As much as I try to focus on changing him regularly, that just doesn't always happen- ask any mom of more than one kid. The result diaper rash. And for the Climber, it can easily and quickly turn into little open cuts and scabs.
So here is the advice. First: change the diaper every hour- even if it isn't soaked. Second: Use a hairdryer to dry the newly wiped and clean area. Third: Do not put any creams or anything on the area.
I have used this process for all 3 of my kids and it works. Within two days the rash is cleared and even at times when there are scabs- they are already in the process of healing. As with many other things in life- early detection is key- the second it looks like diaper rash is happening, start this three step process. It will be much better for you and the baby.