Bye-Bye Antibiotics, Hello Monistat

So first off, I am not talking about myself here.  Noah has a rash all over his genital area that is NOT diaper rash.  I called the doctor, told them what it looked like and they informed that it was a yeast infection.  That is crazy!  I had no idea a kid could develop that, but they told me it was due to the antibiotics, and seeing as he has been on them for about a month and a half, it makes sense.  I know as an adult you can develop that from taking antibiotics, which is why you are supposed to eat yogurt which counteracts with the yeast, but didn't think a kid could get it.  You think his doctor would have told me this.  The poor kid trades one thing for the next.  So now I have to apply Cortizone (which is an anti-itch cream) and Lotrimin (which is an anti-fungal cream you find inthe foot section....very weird) for about a week and it should go away.  I wonder if I could have just used Monistat?  Aside from the yeast infection, he is getting much more used to the tubes in his ears.