There are two main categories of diaper rash. Irritant diaper rash occurs after prolonged periods of skin irritation in the diaper area. Moisture from a wet diaper can be a skin irritant. When feces are combined with urine, the skin can even start to break down. A tightly fitted diaper can rub against the skin and cause chafing and irritation. Perfumes in diapers and wipes and soap residue can also irritate a baby's sensitive skin.

Yeast diaper rash is caused by infection with Candida albicans. In addition to red, inflamed skin, babies develop small, red, raised areas (called satellite pustules) on nearby skin. The presence of these pustules helps doctors differentiate between irritant and yeast diaper rash. Some babies also have a yeast infection of the mouth (called thrush).

Diaper rash is one of the most common skin conditions in infants and small children. The exact incidence isn't known because many cases are never reported to physicians. However, the American Academy of Pediatrics estimates more than half of all babies 4 months to 15 months experience at least one episode of symptoms. Researchers say, at any given time, up to 35 percent of all infants may be affected.

Preventing/Treating Diaper Rash

One of the best ways to prevent diaper rash is to keep a baby's bottom clean and dry. Diapers should be changed frequently. Super-absorbent disposable diapers contain special beads that soak up moisture and keep it away from baby's skin. If using cloth diapers, avoid using plastic or vinyl pants that keep moisture inside the diaper. Use only fragrance-free baby wipes or plain water to clean the baby. In between diaper changes, allow some time for fresh air to circulate around the baby's bottom.

The same tips can also be helpful for treating diaper rash. In addition, over-the-counter barrier creams (like petroleum jelly or zinc oxide) can be placed on the affected areas to prevent skin contact with moisture. Health experts discourage using talcum powder because the infant can inhale the dust particles and have breathing problems.

Many cases of diaper rash clear up in three to four days - even without treatment. If the symptoms don't get better, start to get more severe or are accompanied by formation of blisters or pus-filled sores, a physician should be consulted.

For general information on diaper rash: American Academy of DermatologyAmerican Academy of Pediatrics