What causes diaper rash? Do most babies get it? Does it depend on the kind of diapers you use?
The most common type of diaper rash, called irritant diaper dermatitis, is common indeed. At least half of all infants get diaper rash at some time during their diaper careers. It is most common in the latter half of the first year, perhaps because the infant diet is changing at that time. Diaper rash is particularly likely when a baby has diarrhea.
Diapered skin can become irritated for a variety of reasons. Feces contain an enzyme which can release ammonia from urine. Ammonia makes the pH in the diaper go up. That activates still more fecal enzymes that can harm the skin.
So a wet and dirty diaper left on is a problem. Wet skin itself is a problem. It is easily damaged by friction as the diaper rubs against it. Once the skin is irritated, a common skin organism, Candida Albicans, a simple yeast, often invades and makes matters -- that is, the diaper rash -- worse.
Whatever kind of diaper is used, the diaper should be changed when wet or dirty. Between diapers the skin should be gently cleaned with warm water and a mild soap and patted dry.
If changed frequently enough, either cloth or disposable diapers can be used with success. If rash alone were the only consideration, one would probably choose the new superabsorbent disposables. In comparison studies, babies wearing them seem to have rash less often and less severely.
Diaper rash is also less likely with breast feeding -- one more good reason to go with Mother Nature's infant feeding system.
Dr. Wilson is director of general pediatrics at Johns Hopkins Children's Center; Dr. Joffe is director of adolescent medicine.