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What Is Diaper Rash?

Almost all babies develop a diaper rash — an inflammation of the skin on the buttocks, genitals, and thighs — at some time in their young lives. Although a diaper rash may cause a baby discomfort and even some pain, it is rarely serious. Most cases are of short duration, lasting only three or four days. But sometimes a rash will persist, an indication that a secondary skin condition or infection has developed.

What Causes It?

Diaper rash can be caused by anything that irritates your baby's sensitive skin. The most common source of the problem is urine and stool left in contact with the skin for too long. However, a rash can also be caused by inadequate drying of the baby's skin after a bath. Sometimes, a baby has an allergic reaction to lotions or soaps used directly on the baby's skin or to chemicals in the laundry detergent used to clean fabric diapers.

Seborrheic dermatitis, an inflammatory skin condition that affects the oil glands, can trigger a diaper rash as can thrush, a type of yeast infection. Babies receiving antibiotics for other illnesses are particularly susceptible to thrush-related diaper rash because the drugs allow fungal growth. Eczema, an allergic skin condition, can also occur as a diaper rash in reaction to foods or other allergens.

Caution: Many doctors discourage the use of baby powder because a baby can breathe it in and damage their lungs.