Diaper rash: causes, treatment and when to see a doctor

Diaper rash is red, sore skin in the diaper area. It's very common, and most of the time it comes from pee and poop sitting against the skin plus the diaper rubbing. Frequent changes, gentle cleaning, diaper-free time and a barrier cream usually settle it within a couple of days.

Some rashes need more than that. A thrush rash needs an antifungal cream, and an infected rash needs a doctor. This guide covers causes, treatment step by step, choosing a cream, and when to get help.

What causes diaper rash?

The Royal Children's Hospital Melbourne (RCH) says the most common cause is irritation from constant moisture from pee and poop, plus friction from the diaper. The NHS lists these other causes:

• Diapers not being changed often enough, or rubbing the skin.
• Soap, detergent or bubble bath.
• Baby wipes that irritate the skin.
• Diarrhea.
• Diapers that don't absorb well or let the skin breathe.
• Some medicines.
• Thrush, a yeast (fungal) infection.

The American Academy of Pediatrics (AAP) adds that a yeast rash can develop after a course of antibiotics. Some babies react to an ingredient in diapers, wipes or creams, and rarely a rash is a bacterial infection.

What does diaper rash look like?

The NHS describes red or raw patches on the bottom or the whole diaper area. There may be spots, pimples or blisters, or dry, scaly skin, and your baby may seem uncomfortable. Spots can look red or brown and may be harder to see on brown and black skin, so look closely and watch for signs your baby is sore.

How do I treat diaper rash at home?

Follow these steps at every change until the skin settles:

1. Change the diaper as soon as it's wet or dirty. The NHS advises changing wet or dirty diapers as soon as possible.
2. Clean gently. Use cotton wool or a soft cloth with lukewarm water, as the RCH suggests. Avoid soap.
3. Dry the skin. Pat gently, then let the skin air-dry if you can, as the AAP suggests.
4. Apply a barrier cream. Use it at each change (see the next section).
5. Put on a well-fitting, absorbent diaper. The NHS and AAP advise avoiding tight diapers and plastic pants or covers.
6. Give diaper-free time. The RCH recommends as much diaper-free time as possible. Lay your baby on a towel or waterproof mat.

The NHS suggests bathing your baby daily while they have a rash, but no more than twice a day. Leave out bubble bath, soap and baby lotion.

Which barrier cream should I use, and how much?

The RCH says zinc paste is best. The AAP says zinc oxide and petrolatum (petroleum jelly) are both good choices, and fragrance-free products are best.

Sources differ on how much to apply. The RCH and the AAP suggest a thick layer. The NHS says a pharmacist may suggest a thin layer at each change. Either way, apply it to clean, dry skin at every change.

Don't use these without advice:

• Talcum powder and antiseptic creams. The NHS and RCH say to avoid them on diaper rash.
• Steroid (hydrocortisone) or antifungal creams. The RCH says these are for persistent rash and should only be used on your doctor's or pharmacist's advice.
• Over-the-counter antibiotic ointment. The AAP says not to use it for diaper rash.

How can I prevent diaper rash?

The same habits that heal a rash help prevent the next one:

• Change often. The RCH gives a rough guide of about 5 to 7 changes a day for babies under 12 months. The NHS diaper-changing guide says young babies may need changing as many as 10 or 12 times a day.
• Choose absorbent diapers. The RCH suggests good-quality disposable diapers, as cloth diapers absorb moisture less well. If you use cloth, change them promptly.
• Use a barrier cream at changes if your baby's skin is prone to rash.
• Keep products simple. Use fragrance-free products, and skip bubble bath and scented lotions.

Wipes are a point where sources differ. The RCH says baby wipes can be very irritating and shouldn't be used. The NHS and AAP say fragrance-free, alcohol-free wipes are fine. If your baby's skin reacts to wipes, switch to water.

Is it a thrush rash?

Thrush is a yeast infection that thrives in warm, damp skin. The AAP describes a yeast diaper rash as shiny, bright red or pink patches with sharp edges, sometimes with small pink bumps or pimples. Unlike an irritant rash, it's usually worse in the groin folds.

Thrush rash can appear after antibiotics. It doesn't clear with barrier cream alone, so ask your pharmacist or doctor. The NHS says a doctor may prescribe an antifungal cream for thrush, a steroid cream for redness and soreness, or antibiotics for a bacterial infection.

When should I see a doctor about diaper rash?

These tiers match our when to call the doctor guide.

Call 911 now if your baby:

• Has a rash anywhere that doesn't fade when you press a glass against it.
• Is under 3 months and has a temperature of 38°C or more.
• Is floppy, very sleepy or hard to wake, or struggling to breathe.

These come from the NHS urgent-help guide.

Get medical help today if:

• The rash has blisters, pus, oozing, crusty or open sores, or peeling skin.
• Your baby has a fever with the rash. The NHS fever page advises getting advice for a fever with other signs such as a rash.
• The rash is especially painful, or the skin around it is red, swollen and hot. The AAP says severe pain can be a sign of a skin infection called cellulitis.
• Your baby seems very uncomfortable or unwell.

Talk to your doctor, pharmacist or pediatrician if:

• The rash isn't improving or is getting worse after 2 to 3 days of treatment (AAP), or hasn't improved within a week (RCH).
• The rash is spreading beyond the diaper area.
• It looks like thrush, or your baby is on antibiotics and develops a bright red rash with spots at the edges.
• Rashes keep coming back.

What is worth noting about a diaper rash?

Note when the rash started, any new diapers, wipes, creams or detergents, and any recent diarrhea or antibiotics. A clear photo each day shows whether it's improving. Bring the names of products you've used to the doctor or pharmacist.