My son just got his first rash ever at 6.5 months. The pedi said it looked like yeast when he was at his well baby check up. She prescribed Neostatin cream, but before we got the scrip filled I checked on the boards for ideas, and I've been using a solution of water, a tablespoon olive oil and a few drops of tea tree oil (you can also use lavender) to wash him at diaper changes. It is so much better already. I also leave him diaperless parts of the day, or sometimes diaper on but without the cover to let the air in. It's funny, he got this rash just a day or two after my mom fed him some apple...hmm. I also mostly feed the babe banana and avacado usually.