Diaper rashes are par for the course in a new baby's life. It happens when baby's sensitive skin has been sitting in moisture for too long, and some babies' skin is more sensitive than others’. The best way to prevent diaper rash is to apply a barrier diaper cream that contains zinc oxide, which protects the skin from the moisture in the diaper. Another good way is to let your baby's butt dry out a few times a day — lay down a waterproof pad and just let your baby hang out diaper-less...he may even enjoy it! Sometimes the naturally occurring yeast on the skin can also super-infect a diaper rash, causing painful or itchy little red bumps, usually around the anus or in the folds in the genital area. When you see that, consult your pediatrician for a prescription antifungal cream.