Freshly home from hospital, you\u2019ve finally mastered changing the diaper without making a huge mess and then realize that your baby has a bright-red, irritated bum. There will be a variety of rashes that appear on your baby and diaper rash is certainly going to be one of them.Diaper rashes can be caused by a number of things. Most common is a reaction to a soiled diaper being left on too long. Other things that can cause a diaper rash: chafing from the diaper, yeast infection, bacterial infection, allergic reaction, and seborrheic dermatitis (cradle cap).Treatment of diaper rash is obviously dependent upon the cause of the rash and it will usually take a few days for the rash to clear completely. For immediate relief, expose the bottom to air and use water and a soft cloth to clean the bottom (instead of wet wipes which can be a bit harsh). Strip the baby down in a warm room and have tummy time on a blanket. This could be messy, but the air on babies bottom will help tremendously.If you must put a diaper on, make sure that your babies bottom is well protected by a lubricating barrier such as zinc oxide cream. I am a big fan of Cerave diaper rash cream, which contains zinc oxide as well as other soothing emollients. A cheaper and equally effective option is good old Vaseline (that\u2019s my go to for my baby\u2019s bottom!). Be sure to change the baby as soon as you can when the diaper is soiled. The cream will soothe the skin as well as provide a protective barrier. Be sure that the area is completely clean and dry before putting on a fresh diaper. If you suspect that the diaper is the reason for the rash, try changing the type of diaper you are using. If using cloth diapers, choose a mild, hypoallergenic detergent when washing. Dermatologists like All Free and Clear Detergent for patients with sensitive skin and for babies.When to call the doctor:The rash gets worse or doesn\u2019t clear up in a few daysYour baby has a fever or seems sluggishYou see fluid-filled bumps or crusty areas \u2013 this might be a bacterial infection that requires antibioticsYou notice redness in the folds of the baby\u2019s skin or small red pimples outside of the diaper area \u2013 a sign of a yeast infection which would require antifungal medicine.