Unless your baby is born potty trained, your little one will likely experience diaper rash at least once! You'll know your baby has diaper rash if you notice that the skin on the bottom is irritated, red, and warm to the touch. The most likely culprit of irritation like this is wetness from your baby's own urine. When urine mixes with bacteria from your baby's poop, the result is ammonia, a harsh chemical that can further aggravate skin. Babies with sensitive skin may also experience diaper rash as a result of sensitivity to fragrances in a disposable diaper, or to chemicals in skin care products. Additionally, when your baby is exposed to new foods, the composition of his or her poop may change, in turn, resulting in a rash. Finally, diaper rash can be caused by a yeast infection, which occurs when the yeast fungus grows in the diaper region, nurtured by the warm and wet environment of your baby's diaper. Unlike standard issue diaper rash, this angry, red infection will have slightly raised borders, and may spread as lesions on nearby body parts. The good news about ANY kind of diaper rash? It's temporary and treatable! The quickest way to curb this common affliction is to change your baby frequently, rinsing your infant's bottom with warm water every time. When your baby has a rash-or if he or she's prone to them-it's wise to apply a barrier ointment to your little one's bottom at each diaper change. White zinc oxide and petroleum ointment are both good options to form a protective barrier on your baby's skin. After your baby's bottom is ready, secure the diaper loosely to ensure his skin can breathe. These treatments are all quick and easy, and they should start to work within a few days. If your infant's irritation does NOT respond to such measures, however, it's likely that your baby has a yeast infection. In this case, you'll want to pick up a topical anti-yeast or antifungal cream, like Nystatin, at your local pharmacy. These creams are safe to use at home, but make an appointment with your baby's pediatrician if the infection doesn't respond in a few days. Your baby's doctor will prescribe a stronger ointment, and will also offer insight into preventing yeast infections and diaper rashes in the future!