Diaper rash is skin irritation around the thighs, genitals, buttocks, or abdomen that may make a child cry persistently, especially when a diaper is wet or soiled. The rash is red and may look like the skin has been burned or scalded.
Most of these rashes are caused by the diaper rubbing against the skin, moisture, chemicals in the diaper, or bacteria in the baby's urine or stool.
Almost all babies develop diaper rash at one time or another. Usually simple changes in the diapering or cleaning routine will eliminate the rash. Occasionally a yeast infection causes the rash. If your baby or child has a yeast infection, check with your doctor before you treat it with any product made for an adult.
WebMD Medical Reference from Healthwise