If you have a baby, you have probably already had to deal with at least one diaper rash outbreak. Despite parents' best efforts, diaper rash seems to pop up at seemingly random times. One reason that this problem is so prevalent is because it is caused by so many different things. Learn more about the most common causes of diaper rash below.Sensitive SkinSome babies are simply prone to getting diaper rashes. If your child has a skin condition like eczema, he may be especially susceptible to diaper rash.Changes in the Consistency or Frequency of Stools or UrineDietary changes cause changes in the consistency and contents of stools and urine. As a result, your baby may experience diaper rash. This is especially common in infants who are being introduced to solid foods. If your baby starts urinating or having bowel movements more frequently, he may also develop diaper rash because his skin will be in more regular contact with urine and feces.AntibioticsAntibiotics work by fighting back against bad bacteria. Unfortunately, they also eliminate good bacteria. If the balance of good bacteria is thrown out of whack, problems like yeast infections are more likely to develop.New ProductsIf your baby suddenly develops diaper rash, think about the types of products that you've been using. If you've recently introduced new products like disposable diapers, fabric softeners, laundry detergents, wipes, oils, powders or lotions, they could be to blame. Try switching back to see if the diaper rash goes away.Rubbing or ChafingIt is important not to fasten your baby's diaper or other clothes too tightly. Chafing and rubbing may occur, and diaper rashes are more likely to develop under those circumstances. As soon as your baby outgrows an outfit, pack it away so that you don't inadvertently dress him in it again.Yeast and Bacterial InfectionsYeast and bacteria thrive in warm, moist places. It should come as no surprise that a baby's diaper area can be prone to these types of infections. If your baby develops a stubborn diaper rash that won't respond to regular treatments, you should take him to see a doctor. The only reliable way to cure a diaper rash that has been caused by a yeast or bacterial infection is by using special medications.