If your baby has diaper rash, put away the wipes; they can irritate inflamed skin, says Bruce Robinson, M.D., clinical instructor of dermatology at Lenox Hill Hospital, in New York City. Instead, use a soft cotton washcloth soaked in warm water. Blot the area and, if possible, keep the baby's bottom exposed for a few minutes to air-dry. You can also use a hair dryer set on cool. (Moist, closed environments promote the growth of yeast and fungi.) Next, apply a coating of petroleum jelly or diaper cream, preferably one without lanolin, which can cause an allergic reaction. Using diapers with "breathable" coverings or switching brands can sometimes help. If the rash persists, call your pediatrician.