Babies get yeast diaper rash for several reasons. As with adults, babies who are on antibiotics often turn up with yeast infections in the diaper area. Likewise, breastfed babies whose mothers are on antibiotics are more susceptible to this type of infection. Another cause for yeast infections in babies is the transfer of thrush, an overactive yeast colonization in their mouths, to their diaper area. It is more difficult to control than regular, run-of-the-mill diaper rash in that it usually requires prescription medication and bleaching of towels and other materials that come into contact with the baby's bottom.
Treat diaper rash as if it was the type commonly associated with trapped moisture, sensitive skin, diarrhea or food allergy. Wash the area with water and pat dry. Apply generous amounts of one of these creams: zinc oxide, Acid Mantle (brand name), Hydrocortizone 1% cream, or Soothe and Heal (brand name, by Lansinoh). Watch for significant healing within 24 hours.
If your baby's rash does not improve with the use of the above products, examine it closely for visible symptoms associated with a yeast infection: red, raised, splotchy rash with defined and slightly raised borders, beefy color, and satellite dots all around the area of the main rash. Your baby's skin may also be scaly.
Treat the rash with clotrimazole anti-fungal cream. If that doesn't work, contact your pediatrician for an appointment and a prescription for Nystatin. Some parents prefer acidophilus powder, a natural bacterial powder that fights off yeast.
Keep your baby's hands clean. Bleach cloth diapers, towels or any other materials that come into contact with his diaper area.
Avoid future flare-ups by keeping your baby's bottom clean and dry, giving him time to go without a diaper or other covering and feeding him yogurt with live acidophilus cultures while he is on an antibiotic (and for a few weeks thereafter).