• You leave a wet or dirty diaper on too long
• Your baby’s skin rubs or chafes against the diaper itself
• Your baby gets a yeast infection
• Your baby gets a bacterial infection
• Your baby has an allergic reaction to their diaper

Babies get a diaper rash more often when they:

• Get older -- especially between 9 and 12 months old
• Sleep in poopy diapers
• Have diarrhea
• Start eating solid foods
• Are taking antibiotics, or if you take antibiotics and are nursing
• 
  

 Diaper Rash Treatments

These products aim to soothe a baby's sore skin or create a protective barrier -- or both. Cream or ointment with zinc oxide or petrolatum (petroleum jelly). Smooth it onto your baby's clean, dry bottom before putting on a clean diaper.

• Baby powder. Keep it away from your baby's face. The talc or cornstarch in the powder can cause breathing problems. Place it in your hand, then apply it to the diaper area.
• Antifungal cream, if your baby has a fungal infection
• Topical or oral antibiotics, if your baby has a bacterial infection

Skip the steroid creams you find in the drugstore (hydrocortisone) unless the doctor tells you to use one. They can irritate your baby's bottom even more if you don’t use them the right way.