This is thought to be due to ammonia which is formed by bacterial decomposition of substances such as urea which are present in urine. The leaving on of a wet soiled nappy for too long. Rubber pants which don t allow air in and produce sweat retention and moisture. Occasionally napkin rash may be due to an associated skin condition such as psoriasis, or infantile eczema. Sometime the baby s skin which is very delicate may be reacting to a washing detergent or disinfectant.
Treatment consists of finding the cause and removing it.
The involved skin should be gently cleaned and thoroughly dried. Nappies should be changed as soon as they are soiled and should not be too tight. Disposable nappies may help by being completely clean and free of detergent and soap, although the plastic outer layer of disposable nappies can make baby sweat more and therefore encourage nappy rash. In the case of a fungus a culture of the skin may have to be arranged by your doctor before prescribing an anti-fungal agent combined with a hydrocortisone cream. Treatment of an ammonia rash is by avoiding wet nappies, so the changing of nappies as soon as they are wet is important as also is the use of a medically prescribed antiseptic cream to stop the spread of organisms caused by the bacterial decomposition of urea found in urine.