Diaper Rash

Diaper Rash

Diaper Rash

When you change your baby’s diaper, the last thing you want to find is a red little bottom. Diaper rashes are common in babies between 4 and 15 months old. Some types of diaper rash can be painful. Learn what causes diaper rash and what you can do to protect baby's skin.

What is diaper rash?

Diaper rash, also known as napkin or nappy rash, is found on the skin inside your baby's diaper area. The skin can be paler or darker than the surrounding skin. The rash may be mild with minor bumps or spots or it may be red and irritated with blisters or broken skin. 

It may look (and can be) painful but a diaper rash is usually not serious or contagious and can be easily treated.

Who gets diaper rash?

Diaper rash mostly affects babies between the ages of 4 and 15 months, with the peak age for diaper rash being between 9 to 12 months. Diaper rash is more common...

  • In formula fed babies, than breastfed babies.
  • Once a baby starts eating solid foods.
  • If a baby has a sensitive skin condition, such as eczema.
  • When a baby is taking antibiotics (or a nursing mother is taking antibiotics).
  • If diapers are not changed regularly.
  • When cloth diapers are used.
  • When a baby has frequent, watery bowel movements.

Babies are also more prone to diaper rash when they have a cold or are unwell for any other reason, because their body's natural defenses are not working as well as they should at that time.

While your baby needs to wear diaper, no matter how careful you are, sooner or later she's likely to develop a diaper rash.

How long will diaper rash last?

This depends on the cause of the rash and how it is treated. Mild cases of diaper rash may clear up in 3 to 4 days even without treatment. Some diaper rashes takes several days to improve with treatment and severe diaper rashes could last for weeks.

General tips on treating diaper rash 

Prevention and treatment of diaper rash greatly depends on reducing the amount of time your baby's skin is exposed to irritants. For the majority of diaper rashes general treatment is all that is required.

  • Change diapers as soon as you know they are wet or dirty.
  • Gently clean your baby's skin. Don't rub (as this may further damage tender skin).
  • Gently pat dry with a clean, soft towel.
  • Allow some diaper-free time for 5 or 10 minutes (or longer), 3 or 4 times each day.
  • Apply a protective diaper rash cream. Don't use petroleum jelly, talc or cornstarch while treating a diaper rash. Don't use creams that contain steroids (cortisone or hydrocortisone) unless instructed to do so by your baby's doctor.
  • After changing your baby's diaper, wash your hands well.

When the rash is mild

  • Apply a diaper cream each time you change your baby's diaper e.g. zinc oxide based diaper cream, to keep dampness away from her.
  • Allow the cream to dry before replacing her diaper.

When baby's skin is broken

  • Avoid baby wipes and soaps (because they can sting an already tender little bottom).
  • Clean your baby's bottom with a diluted sorboline solution, made up of 1 teaspoon of sorboline cream in 4 oz of cooled boiled water (shake well). After cleansing her skin, dab a diluted solution of baking soda (sodium bicarbonate) over the raw area using a cotton wool ball. To make the baking soda solution, dissolve 1 teaspoon of baking soda in 8 oz of cooled boiled water. (Make up a fresh batch of both sorboline and baking powder solutions each day).
  • If your baby has watery bowel movements, clean her as gently as you can, then soak her raw little bottom in a few inches of warm water in a bath, to make sure her skin is thoroughly clean. Add 2 tablespoons of baking soda to the water. This is soothing to her tender skin, it also alters the pH (acid balance) of her skin making it less appealing for bacteria to grown on.
  • Allow sufficient time for her skin to dry thoroughly before applying protective diaper cream.
  • Aviod the use of zinc oxide diaper creams on broken skin. (It can further irritate raw skin).

When diaper rash is troublesome

A diaper rash could be due to one or a combination of different reasons. Because the treatment of diaper rash is very similar no matter what the cause, it's not always necessary to pinpoint the exact reason (or reasons), especially if the rash is mild or seldom occurs.  However, if your little one is often troubled by diaper rash it may be well worth your efforts to discover the cause so that you can take active steps to prevent its return.

The scalding effects of urine (pee) and stools (poop) are responsible for the majority of diaper rashes in babies. These rashes can become more troublesome once your baby... 

  • Starts on solid foods.
  • Is introduced to new food.
  • Is changed from breast milk to formula.
  • Starts on cow's milk. 

Listed below are the many possible causes for diaper rash to develop and additional tips treating specific diaper rashes.

What causes diaper rash?

Basically anything that irritates your baby's skin or alters the protective layer of her skin can cause a diaper rash. Common reasons for a diaper rash to develop include... 

  • Urine (pee)
  • Stools (poop)
  • Moisture
  • Chaffing
  • Skin infections
  • Skin conditions
  • Ointments, creams, lotions and powders
  • Chemical irritants
  • Allergic reaction

1. Urine (pee) 

Anything that alters the pH (acid balance) of your baby's urine, either before she pees or after her urine has soaked her diaper, can cause the urine in her diaper to scald her bottom if it remains in contact with her skin for too long. 

Prolonged exposure 

Your baby's urine is sterile (there are no germs in it), so when her pee is fresh it doesn't harm her skin. But if her diaper is left on too long, bacteria normally present on her skin or on the diaper can alter the pH balance of the urine when it's in her diaper. Once the pH balance of the her urine in her diaper has changed, it can then burn or sting her skin.


Foods can alter the pH balance of your baby's urine and stools, which significantly increases the risk of a diaper rash developing. Once your baby has started on solid foods this will increase the renal solute (minerals and urea) that her kidneys need to filter from her blood, which is then flushed out with her urine.


The pH balance of your baby's urine can also be altered when she's teething. So this can be a time when her skin may become irritated and/or a diaper rash develops. This is generally only a short term problem which occurs for a few days around the time her tooth (or teeth) are breaking through the surface of her gums. 

What a urine rash looks like in babies

In a mild case the affected skin is bumpy and shiny and has a blotchy, parchment-like appearance. The color of the rash is generally only slightly different to the rest of your baby's skin. However, with prolonged exposure her skin may become red and irritated. Repeated, prolonged exposure of wet diapers may result in a severe rash, where her skin may peel or blister and slough off.

This rash appears on areas with the most contact to the urine in her diaper. This means the rash will be more obvious on the contours of your baby's skin, such as her genital area and buttocks if she sleeps on her back or on her genital area and abdomen if she sleeps on her tummy. The folds of her skin are not affected.

This type of diaper rash, which frequently occurs on babies over 7 months old, is often linked with a strong smell of ammonia. It is more common when cloth diapers are used. 

Additional tips on treatment

  • If cloth diapers are used, try using waterproof diaper liners during the day and a disposable diaper overnight.
  • If you already use disposable diapers, try using one of the more expensive gel based disposable diapers overnight.
  • Once your baby has started eating solid foods increase her water intake to dilute her urine.

2. Stools (poop)

Your baby's stools are more irritating to her skin than urine (pee). Your baby's stools naturally contain irritating substances which can lead to a diaper rash if it remains in contact with skin for too long.

Anything that alters the pH (acid balance) of your baby's stools, which then cause stools to burn or sting her skin, can potentially cause a diaper rash even in a very short period of time. An increase in the frequency of her bowel movements may further add to the problem by increasing the amount of time her bottom is exposed to the irritating effects of her stools.

Changes to diet

Many foods alter the pH (acid balance) in your baby's stools and this may cause a diaper rash if she has sensitive skin. This type of rash often occurs when a new food is introduced to her diet. Acidic foods, particularly citrus fruits or tomato based foods are often to blame. Different foods can contribute to the overall effect.

Formula fed babies are more prone to diaper rash than breastfed babies because formula results in more alkaline stools.

Digestive immaturity

Up until around the age of 4 months, your baby's digestive system lacks the ability to produce sufficient quantities of the various digestive enzymes that are necessary to breakdown foods other than milk (breast or formula). Because foods are then poorly digested, starting solids or fruit juices too soon or too much fruit juice may result in an altered pH balance of her stools as well as watery bowel movements. (See starting solids and carbohydrate intolerance).

Digestive disorders

1 - 2% of babies develop a food or milk allergy. Approx 8% experience  intolerance to a particular food or milk. Both of these conditions will result in a change in the pH balance of stools, as well as frequent watery bowel movements (in addition to other symptoms), so diaper rash is commonly seen if a baby experiences either these digestive disorders. (See milk allergy & intolerance).

It can be extremely difficult to pinpoint the exact food that is causing the trouble, as an allergic reaction rarely occurs with the first exposure to a particular food, rather the reaction increases in intensity with repeated exposure. A food or milk intolerance can occur with the first exposure, but it is often 'dose related', meaning a little of particular food is unlikely to cause a problem, whereas a lot can cause symptoms.

The scalding effects of poop can also affect exclusively breastfed babies. In babies less than 5 months of age, this is more often due to lactose overload and less commonly due to an allergy or intolerance to a particular food in the mother's diet. 

Gastro-intestinal infection 

The risk of developing a diaper rash increases 3 fold when a baby has frequent watery bowel movements (diarrhea) due to a gastro-intestinal infection (gastroenteritis, stomach flu, tummy bug, infectious diarrhea). This is because the pH balance of stools is altered at this time.  Frequent diarrhea increases the time skin is exposed to the scalding effects of stools. 


Many prescribed medications, over-the-counter drugs, mixtures or herbal remedies can alter the pH balance of your baby's stools and/or result in frequent watery bowel movements, both of which increase the risk of a diaper rash developing. These include...

  • Some colic mixtures
  • Some 'reflux' medications
  • Antibiotics (even where a nursing mother is taking them)

What this rash looks like in babies

This rash is bright to dark red and is generally confined to areas which come into direct contact with poop. If your baby's poop is soft or paste consistency, the rash will appear around her anus. However, if her bowel movements are watery, fecal matter (poop) can sometimes collect in the folds of her skin, including her labia (skin folds covering her vagina). The redness and irritation of her skin will settle quickly once the poop has been removed and her skin is thoroughly cleaned.

Additional tips on treatment for diaper rash

  • Take care to clean in the folds of your baby's skin. Particular care needs to be taken when cleaning a baby girl's diaper area. Always clean from front to back .
  • Apply a protective layer of zinc oxide based diaper cream while your baby has diarrhea.
  • Don't add further new foods to your baby's diet until the rash has gone.
  • If your baby is on medications, discuss this with your baby's doctor or pharmacist.

3. Moisture

If your baby's diaper area remains moist, this increases the risk of a diaper rash developing. Anything that restricts air circulation, such as...

  • waterproof or plastic pants (used with cloth diapers)
  • disposable diapers with thick plastic outer coating; and/or
  • the use of thick diaper creams of ointments 

... may encourage your baby's skin to sweat underneath.

Moisture alone does not cause a diaper rash but prolonged moisture from inadequate drying, sweating or urine (pee) increases the risk of your baby developing a diaper rash because it can affect the protective layer of her skin. (Remember how your hands look and feel if they remain wet for too long). Moisture also encourages the growth of bacteria and yeast on your baby's skin.

Prickly heat

Prickly heat, also known as 'sweat rash', is a common condition in babies caused by blocked sweat ducts which become inflamed. Some babies are more prone to prickly heat than others. (Not all sweating results in prickly heat. The incidence of prickly heat is increased when babies become overheated. Common reasons for a baby to become overheated include... 

  • hot weather
  • an overheated house or car
  • hot baths
  • overdressed i.e. too many clothes or covers 

What prickly heat looks like in babies

Your baby's skin may be red, spotty and moist. The rash appears like hundreds of pin-head sized raised spots. Some skin eruptions may contain pus and appear 'pimply'. The rash can appear in one area or cover your baby's entire diaper area.  A rash may also be visible on other parts of your baby's body as well (although not necessarily) such as the back of her neck, face, abdomen or elsewhere. The rash often appears to worsen during the day.


Intertrigo is the name given to an inflammation of body skin folds and creases, which is caused by heat and moisture trapped in areas where skin rubs together. This type of rash is more common in chubby babies.

What intertrigo looks like in babies

This rash may be seen in the deep folds of your baby's diaper area. The skin in body folds and creases is moist, red and inflamed. A similar rash may also (but not always) be seen on other parts of your baby's body where there is skin to skin contact such as upper thigh folds, under her arms or neck.

This rash can easily be confused with a yeast infection. However, a yeast infection will often develop secondary to skin irritation caused by intertrigo.

Additional tips on treatment

  • Cool your baby by bathing her frequently in tepid water, without soap.
  • Dry carefully between the folds of skin.
  • Air your baby's diaper area as much as possible.
  • Make sure her skin is dry before applying diaper creams or lotions and make sure the cream or lotion is dry before replacing her diaper.
  • Avoid the use of thick occlusive diaper creams and gels (see No. 8 below).
  • Use a zinc oxide based cream on a rash due to intertrigo but not on  a rash due to prickly heat.
  • Avoid overdressing your baby. Dress her is loose fitting cotton clothing.
  • Lowering the room temperature may help.
  • If cloth diapers are used, use plastic pants only when really necessary.
  • If disposable diapers are used, try a different brand, with an outer layer that allows the diaper to 'breathe'.

4. Chaffing

Chaffing, due to friction, can result in a breakdown of your baby's skin, which may then leave it vulnerable to a secondary skin infection. A diaper rash due to chaffing can appear in different places on your baby's diaper area depending on what's causing the friction.

What chaffing looks like in babies

Chaffed skin will appear red and puffy.

Chaffed skin around your baby's legs or around her abdomen may be due to the plastic lining of disposable diapers rubbing against her skin as she moves or the elastic in plastic pants being too tight. Chaffed skin in the folds of her groin may be due to the use of talc or cornstarch powders. If your baby is very mobile, chaffed skin in places other than folds may be due to the friction of the diaper as it rubs against her skin. This can occur if the diaper is wet or dry, particularly if the diaper is rough.

Additional tips on treatment

  • Avoid the use of talc and cornstarch powders.
  • Don't fasten her diaper too tight.
  • If cloth diapers are used, drying them in a clothes drier leaves them softer than drying them on a clothes line.
  • Fold the plastic edges of disposable diapers away from your baby's body. 

5. Skin infections

Germs normally present on your baby's skin or in her poop can cause a secondary infection if her skin's natural protective barrier has been altered for any reason.

Yeast (thrush)

A yeast infection is almost always present in more severe diaper rashes as it often develops on top of other diaper rashes. Even where a diaper rash did not already exist, a yeast infection may develop while your baby is taking antibiotics (or a breastfeeding mother is taking them).

What thrush looks like in babies

The rash starts as small red spots that become more numerous and then form together as a raised bright red rash with distinct edges. Smaller spots may appear outside the main area. The rash is most often seen in the folds of skin around a baby's groin and/or anus and almost never on the buttocks (but it can). 

A yeast (thrush) infection should be suspected in any diaper rash that has not improved dramatically within 3 days of using 'General tips on treating diaper rash', described above.


  • See our article on thrush for more on prevention and treatment.  


Although rare, a bacterial infection can also affect your baby's diaper area. Impetigo is the most common bacterial infection in the diaper area.

What impetigo looks like in babies

Yellow-brown crusty patches or coin-sized pus filled pimples or blisters can appear on your baby's buttocks or lower abdomen. The rash can start from your baby's umbilical cord or anus then spread from there.


  • See your baby's doctor for diagnosis and advice regarding specific treatment. Antibiotic treatment may be necessary.
  • Follow 'General tips on treating diaper rash', described above.

6. Skin conditions

Rashes that appear on other parts of the body can be exaggerated in your baby's diaper area. Many skin conditions can either begin or are more noticeable in your baby's diaper area. A diaper rash may be due to a skin condition such as...


Psoriasis is a common skin condition that affects 2% of the population in the United States. Psoriasis is a non contagious, inherited skin condition that can first appear in infancy (although it more often develops later on).

What psoriasis looks like in babies

The rash first appears around the genital and anal areas and then may spread to other areas of the body. In a warm humid environment (e.g. area covered by a diaper) psoriasis appears like plaques with clearly defined edges. The affected skin is salmon-colored, thin, smooth and shiny. (In the early stages this conditions is sometimes mistaken as a yeast infection).


Seborrheic dermatitis is an inflammatory skin condition that affects the oil glands in the skin. This type of rash usually starts on the scalp as 'Cradle cap'. However, it can sometimes begin in the diaper region and then spread upwards. This condition occurs mostly in the first 2 to 3 months of life. 

What seborrhea looks like

Seborrheic dermatitis, while rare, is one of the worst looking diaper rashes. It appears as a deep red rash that is raised, rough, thick and greasy. It may extend from the lower abdomen to the groin and is often worse in the skin folds.


Infantile eczema is an allergic skin condition. The cause of the allergy is often not identifiable. Dust mite, pollens and/or moulds commonly cause allergic skin reactions in sensitive babies. Only 10% of cases of eczema are thought to be due to an allergy to food or milk. 

What eczema looks like in babies

This type of rash shows up as red scaly patches on the legs and in the groin area. This rash may turn up in other parts of the body first and spread to the diaper area between 6 and 12 months of age. 


See your baby's doctor for diagnosis and advice regarding treatment. 

7. Ointments, creams and powders

Anything that comes into contact with your baby's skin can potentially cause a diaper rash. This also includes many of the creams, lotions, ointments and powders that are designed to treat diaper rash.

Creams, lotions, ointments and powders can irritate your baby's skin by causing chaffing from friction. Thick creams can encourage her skin to sweat underneath. A diaper rash cream can also become a source of infection if it becomes 'contaminated' by germs that may be transferred from your hands to the cream at the time of changing a dirty diaper.  Although very rare, some babies with sensitive skin can develop an allergic reaction to a diaper rash cream.  (Many commercially available diaper rash creams contain peanut or archis oil, often undeclared on the label). 

Zinc oxide based creams should not be used on broken skin as it can make the rash worse, but it can be used after the rash has gone to prevent reoccurrence.

Petrolium Jelly (Vasoline) was once a favorite, but it is no longer recommended for use on a baby's skin because it is too occlusive i.e. it does not allow adequate aeration of the skin. Prolonged use can result in excessive softening and thinning of the protective layers of the skin, increasing the risk of a secondary yeast (thrush) infection developing.

Talc powder can cake in your baby's creases, particularly the groin, and result in skin chaffing from friction. Contrary to popular belief talc powder does not absorb water and has no anti-fungal or anti-bacterial properties. If inhaled, talc could irritate your baby's lungs. Because talc powder potentially causes "more harm than good" it is best avoided altogether.

Cornstarch powder can absorb moisture, however it also tends to cake once it becomes wet and this can irritate your baby's skin and promote skin breakdown from chaffing. Cornstarch may also help bacteria and yeast to grow on your baby's diaper area because it provides a source of food for germs. 

Creams which include emulsifiers (often found in zinc oxide based creams) are usually soap or detergent based. Although they appear in low quantities, they are nonetheless capable of causing irritation.


  • Zinc oxide (without emulsifiers) or other diaper creams should be left to Dry on your baby's skin before putting a new diaper on.
  • Do not use baby talc powder, cornstarch or petroleum jelly (Vasoline).
  • Do not use zinc oxide creams on raw or oozing skin.
  • Avoid contaminating creams and lotions with germs by making sure your hands are clean before touching them.
  • Throw away old diaper creams following a diaper rash that involves a bacterial or yeast (thrush) infection.

9. Allergic reactions

The least common cause of diaper rash is an allergic reaction. This can include reactions to any of the chemical irritants, ointments, creams, lotions and powders that come into contact with your baby's skin.


  • See your baby's doctor for diagnosis and advice on treating allergy rashes.
  • If your child has allergies, talk to a pharmacist about a suitable diaper cream.

8. Chemical irritants

A diaper rash may develop soon after you start using a new product.  Many cleaning products can have an irritating effect when they come into contact with your baby's delicate skin.

What chemical irrigation looks like in babies

The rash will appear on any area where the diaper comes into direct contact with the skin (the exception being when the reaction is due to bath soaps).  It most often affects the contours of her skin but not the folds. The color may be only slightly different to the rest of her skin or it could be red and irritated.  The skin may appear bumpy and blotchy.

Cloth diapers

Some of the products used to wash cloth diapers such as washing powders, soaps, fabric softeners, diaper rinses or bleaches can cause a diaper rash.  These products may irritate your baby's sensitive skin if they remain in the diaper.


  • Use a gentle washing powder of pure soap .
  • Avoid fabric softeners.
  • Rinse diapers twice.
  • Add 1/2 cup of vinegar to the final rinse. This alters the pH (acid balance) of the diapers making them less appealing for germs to grow on.
  • Drying cloth diapers in a clothes dryer leaves them softer than drying them on the line.
  • Use special soft waterproof diaper liners to keep moisture away from your baby's skin.
  • If possible use disposable diapers while treating a severe diaper rash. 

Disposable diapers

Disposable diapers are better at keeping wetness away from your baby's skin than cloth diapers. However, although rare, some babies skin can develop react to the materials used in disposable diapers. 


  • Different diaper manufacturers use different moisture absorbing materials, so it may be necessary to try a different brand.

Baby wipes 

Some baby wipes, which contain spirit (alcohol) or perfume, can irritate your baby's skin. Others can contain cleansers that remove the natural protective oil from your baby's skin, making the area more prone to a diaper rash from other causes.


  • Do not use baby wipes that contain alcohol or perfume .
  • Avoid the use of wipes while treating a diaper rash, as they can sting tender skin. Instead use cotton wool and water to clean urine from her bottom or a diluted sorboline solution to clean poop from her bottom. (Add one teaspoon of sorboline cream to 4 ounces of cooled boiled water and shake well. Make a fresh 'brew' each day).


Medicated and perfumed soaps may irritate or make your baby's skin feel dry. Although thorough cleaning of your baby's diaper area is recommended, rigorous cleaning or the use of soaps can decrease her skin's natural protective barriers, making it more prone to a diaper rash. 


  • Avoid the use of soaps when cleaning your baby's bottom.
  • Use a hyper-allergenic baby wash or diluted sorboline to bath your baby.

When to see a doctor

  • If your baby's diaper rash gets worse or isn't better after 3 days of treatment using 'General tips for treating diaper rash', described further above.
  • If the rash has blisters, crusted areas, sores, boils or bleeding.
  • If your baby has a fever or appears unwell.
  • If your baby also has a rash on other parts of her body. 

Written by Rowena Bennett.

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