What causes diaper rash?

Over the years diaper rash has been blamed on many causes, such as teething, diet, and ammonia in the urine. However, we now believe it is caused by any of the following factors:

• Too much moisture

• Chafing or rubbing

• When urine, stools, or both touch the skin for long periods

• Yeast infection

• Bacterial infection

• Allergic reaction to diaper material

When skin stays wet for too long, it starts to break down. When wet skin is rubbed, it also damages more easily. Moisture from a soiled diaper can harm your baby's skin and make it prone to chafing. When this happens, a diaper rash may develop.

More than half of babies between 4 and 15 months of age develop diaper rash at least once in a 2-month period. Diaper rash occurs more often when

• Babies get older—mostly between 8 to 10 months of age.

• Babies are not kept clean and dry.

• Babies have frequent stools, especially when the stools stay in their diapers overnight.

• Babies have diarrhea.

• Babies begin to eat solid foods.

• Babies are taking antibiotics, or mothers of nursing babies are taking antibiotics.

When do I need to call the doctor?

Sometimes a diaper rash needs medical attention. Talk with your baby's doctor if

• The rash does not look like it's going away, or it gets worse 2 to 3 days after treatment. (See What can I do if my baby gets diaper rash?)

• The rash includes blisters or pus-filled sores.

• Your baby is taking an antibiotic and has a bright red rash with red spots at its edges. This might be a yeast infection.

• Your baby has a fever along with a rash.

• The rash is very painful. Your baby might have a skin condition called cellulitis.

What can I do if my baby gets diaper rash?

If your baby gets diaper rash (and to prevent future diaper rashes) it's important to keep the area as clean and dry as possible. Change wet or soiled diapers right away. This helps cut down how much moisture is on the skin.

• Gently clean the diaper area with water and a soft washcloth. Disposable diaper wipes may also be used. Avoid wipes that contain alcohol and fragrance. Use soap and water only if the stool does not come off easily. If the rash is severe, use a squirt bottle of water so you can clean and rinse without rubbing.

• Pat dry; do not rub. Allow the area to air-dry fully.

• Apply a thick layer of protective ointment or cream (such as one that contains zinc oxide or petroleum jelly). These ointments are usually thick and pasty and do not have to be completely removed at the next diaper change. Remember, heavy scrubbing or rubbing will only damage the skin more.

• Do not put the diaper on too tight, especially overnight. Keep the diaper loose so that the wet and soiled parts do not rub against the skin as much.

• Use creams with steroids only if your baby's pediatrician recommends them. They are rarely needed and may be harmful.

• Check with your pediatrician if the rash

  • Has blisters or pus-filled sores

  • Does not go away within 2 to 3 days

  • Gets worse

  NOTE: Never leave your baby alone on the changing table or on any other surface above the floor. Even a newborn can make a sudden turn and fall to the floor.

Which type of diaper should I use?

Diapers are made of either cloth or disposable materials. Because there are no current studies about what type of diaper does a better job of keeping the diaper area dry, your choice may be based on different factors, including personal preferences, cost, and convenience, or feedback from family and friends. Both types of diapers have different effects on the environment. Washing cloth diapers uses energy, water, detergent, and time; disposable diapers end up in landfills.

Whether you use cloth diapers, disposables, or both, always change diapers as needed to keep your baby clean, dry, and healthy.

If you choose not to hire a laundry service and to wash your own cloth diapers, you will need to presoak heavily soiled diapers. Remember to keep and wash soiled diapers separate from other clothes. Use hot water and double-rinse each wash. Do not use fabric softeners or antistatic products on the diapers because they may cause rashes on sensitive skin.

The American Academy of Pediatrics (AAP) is an organization of 67,000 primary care pediatricians, pediatric medical subspecialists, and pediatric surgical specialists dedicated to the health, safety, and well-being of infants, children, adolescents, and young adults.