Diaper rash is an inflamed, red rash on a baby's buttocks, thighs, and genitals. It's usually a mild bacterial infection, but it also can be an allergic reaction to detergent the diaper was washed in or to a chemical or material used in a disposable diaper. Children may also be allergic to soaps or chemicals, such as bubble bath, lotion, or other products that contain fragrances and chemicals. It's important to try to get rid of the diaper rash quickly so the child's urine doesn't further break down into ammonia and cause a severe infection. Treatment of diaper rash includes washing the area with water and unscented mild soap, and drying thoroughly. If possible, expose the area to air as long as possible without covering it up. You can apply an over-the-counter ointment or a doctor may prescribe an antifungal cream if the rash is more severe. You can help a child avoid diaper rash by using very absorbent diapers, changing them frequently, and by avoiding plastic-covered diapers and plastic pants, which don't allow the body to receive enough air. If the rash is severe, if it hasn't cleared up after three days, or if the child's developed a fever or isn't eating normally, contact a healthcare professional.