What causes diaper rash?

Conditions that create an environment for diaper rash

The primary cause of diaper rash is prolonged and increased exposure to wetness/moisture against the skin. Other contributing factors to diaper rash are:

• The closed environment created by the diaper. Diapers are usually snug fitting. This results in little air reaching baby’s diaper area. This causes baby’s skin to become warmer and moister and therefore have a higher pH (which is a measure of acidity vs. alkalinity) than elsewhere in the body. Excessive moisture in the skin makes it more easily penetrated by irritants and more vulnerable to swelling.
• Chafing from friction or rubbing. Friction can weaken the protective barrier of the skin. Moist skin is more vulnerable to friction than dry skin, so the diaper area is particularly prone to this problem. Friction between the diaper and the skin, two areas of skin (such as in skin creases and folds), and constant wiping and cleaning in the diaper area can facilitate the penetration of irritating substances into the skin.
• Prolonged contact of the skin with urine, feces or both. The enzymes in feces (protease and lipase) may irritate baby’s tender skin. In addition, feces contain organisms that can cause skin infection. Urine further irritates the diaper area. As urine breaks down, it releases ammonia. This causes the pH of the skin to rise (in other words, to become increasingly basic, or alkaline) and the enzymes from baby’s stool to become more active. This may result in tissue/skin damage and lead to diaper rash.