Nappy rash Dr Trisha Macnair Almost every baby at some point will be affected by a sore bottom from constant nappy changing.

In this article

What is nappy rash? Symptoms

Causes and risk factors Treatment and recovery

Nappy rash is a general term that covers any sort of rash or skin condition occuring in the nappy area, and affects almost every baby at some point.

Nappy rash causes redness in the nappy area, sometimes spreading down the legs or up to the abdomen. The redness may be spotty, blotchy or cover a larger area.

In nappy rash due to irritant dermatitis the flexures (or folds) of the skin may not be affected because the skin there doesn't come into contact with the irritant chemicals.

In a Candida rash the skin may be inflamed with extra spots around the edges, called satellite lesions.

There are several causes of nappy rash. Most common is irritant dermatitis, which is inflammation of the delicate skin caused by contact with chemicals in urine or faeces. This is much less common these days due to disposable nappies, which are more absorbent and use a membrane to separate the wet nappy from the skin (although a similar membrane or layer can also be used in non-disposable nappies).

The condition can occur if nappies are not changed frequently enough or the baby has diarrhoea. Candida (a yeast) may complicate the rash. However, irritant dermatitis can occur even when the nappy area is frequently cleaned.

Nappy rash may also be caused by seborrhoeic dermatitis, a condition of unknown cause where there's excessive production of sebum by the sebaceous glands. It starts on the scalp as yellow waxy scales and is commonly called cradle-cap. It is not itchy and children are unperturbed by it. Many children have cradle-cap, it is unusual for it to spread.

Very rarely recurrent nappy rash is a sign of a serious underlying condition affecting the immune system or zinc metabolism.

Treatment includes keeping the nappy area as clean and dry as possible. If possible, let the baby roam without a nappy for a few hours each day, exposing the skin to warm dry air.

Simple treatments such as zinc creams and ointments, which are available from the pharmacy, may be effective in treating or preventing nappy rash.

In more severe cases, your doctor may recommend a steroid cream for severe irritant dermatitis, or anti-fungal treatment for Candida nappy rash.

If your baby has nappy rash, change nappies as soon as they're wet or dirty. Before putting a fresh nappy on, apply water repellent barrier creams to the skin. If the rash persists or gets worse, get medical advice.

This article was last medically reviewed by Dr Orlena Kerek in February 2009