Nappy rash is most often caused by the baby's skin coming into contact with urine, especially when a soiled nappy is not quickly changed. Some babies are particularly susceptible to it, for example due to having sensitive skin.
Nappy rash may be triggered by:
- The formation of ammonia when urine comes into contact with microbes on the baby’s skin.
- Plastic pants that don’t allow moisture to move away from the baby’s skin.
- Nappies that chafe the baby’s skin.
- Contact irritation from chemicals in laundry powder, fabric softener, baby wipes, soaps or lotions.
Babies with a personal or family history of other skin problems (e.g. cradle cap or eczema) are more likely than others to experience nappy rash.