FAQs can be found at the end of this blog.

Do food allergies cause eczema? If a baby has eczema, are they more likely to develop a food allergy? Vhi consultant paediatrician, Dr Caroline Lhopital, explains the important eczema facts, how it’s linked to food allergies, and what parents need to know about treatments and care. 

What is eczema?

Eczema (short for atopic eczema, sometimes also called atopic dermatitis) is a skin condition that causes inflamed, dry, itchy and cracked skin. It impacts the skin’s ability to act as a barrier to things in our environment. Though eczema has a link with allergies in general, it is primarily a skin condition and can’t be cured by allergy medications or diet alone.

The exact causes of eczema aren’t fully understood, but research shows it could be a mix of genetic and environmental factors. Eczema causes the top layer of the skin to be more brittle, which causes loss of moisture and makes it easier for exterior things to penetrate and irritate the skin.

On light skin, eczema can appear reddish in colour, and dark brown, purple or greyish on darker skin tones. It can develop at any age, sometimes within the first few months of life. The main symptom of eczema is itching, and for some people, it can be severe and disruptive. Eczema typically affects the face, neck and trunk in young babies, and the elbows, hands, knees and ankles in older children and adults, but really, it can appear anywhere.

Your healthcare provider will be able to diagnose your baby with eczema by examining their skin, and this won’t usually require blood or skin tests. There is no cure for eczema, but it usually improves as the skin matures. In the meantime, there are plenty of treatments to help, starting with regular moisturisers and specific creams to reduce the inflammation when it happens.

The link between eczema and food allergies

As I said above, eczema is not an allergy, but the two are closely related. Here are some facts to help explain the relationship between them:

• Some babies with eczema can be more likely to develop food allergies, especially if there's a family history of asthma, hay fever, or other allergies. This is because eczema weakens the skin’s barrier, allowing allergens to enter and trigger an immune system response. So, it’s not that eczema causes food allergies, but it can be an early sign of a sensitive immune system, which is linked to food allergies. 
• Think of our skin as being constantly monitored by patrol cells ─ like guards doing their rounds. If they spot a troublemaker jumping over the barrier, they report it to the immune system, which then produces antibodies against the substance. This is good when it comes to viruses or bacteria, but less so when the culprit is a harmless food molecule!
• The immune system can remember threats. So, when it produces antibodies to fight allergens, this is called "sensitisation." After someone is sensitised, meeting that allergen again might cause an allergic reaction ─ either right away or later on.
• Eczema can get worse for many reasons, such as stress or illness. Allergic reactions to food, especially delayed ones, can also trigger a flare-up or make existing eczema more severe. Some babies with severe eczema seem to improve when certain foods are removed from their diet. This has led to the common belief that changing a baby’s diet (like avoiding dairy) can help manage eczema symptoms. But it’s not recommended to remove food from your baby’s diet to try and help their eczema without talking to your healthcare provider first. 

Will all babies with eczema develop food allergies?

No, fortunately not. In fact, only a small percentage will, usually amongst babies with extensive eczema and/or eczema that started very early in life. And even for those, recent research has shown that if you can teach the immune system that food isn’t a threat, it can prevent food allergies altogether. This is backed by studies such as the 2015 LEAP study and its follow-up 2024 study, which found that babies at high risk for peanut allergy (babies with severe eczema, egg allergy or both), reduced their risk of peanut allergy by more than 80% when they were eating peanut foods early and regularly (compared to avoiding peanuts completely).

This is why it’s now recommended to introduce allergenic food such as egg, dairy, wheat, and nuts into your baby’s diet early on ─ this way it has a better chance of being accepted as ‘regular food’ by their immune system, and not a threat of some kind. This is especially important if your baby has eczema and/or there’s a family history of allergies in the family.

Weaning when your baby has eczema

Weaning is what we call the process of introducing a baby to solid food. As with every baby, it’s advised that babies with eczema start weaning at four to six months old, as long as they are developmentally ready [1].

Some extra precautions are needed for babies with eczema:

• First, make sure the food goes only into their mouth and not on their skin: use a spoon and try to avoid them touching and smearing food on themselves if it’s the first time they’re having it. Use Vaseline around their mouth to protect the skin while you’re feeding them.
• Avoid using skin products that contain food molecules your baby hasn’t eaten yet (there’s oat milk and cow’s milk in some popular baby bathing products, for instance). Wash your hands well before applying moisturisers on your baby’s skin.
• Try, as best you can, to start a new food on a day your baby’s eczema is well controlled. This is because it might be difficult to spot a mild reaction if your baby’s skin is already flared up. Don’t hesitate to plan a visit with your healthcare provider to get their eczema under control before you start.
• Start with a very small quantity of the new food and increase it over time. Introduce foods one by one, leaving up to two days between new foods so there’s enough time to observe for delayed allergic reactions.
• Observe your baby for signs of allergic reactions:
  • Immediate allergic reactions happen in a few minutes to two hours. They manifest as swelling around the mouth, hives, vomiting, and sometimes, breathing difficulties. If your baby has an immediate reaction, stop the food immediately and seek advice from your healthcare professional.
  • Delayed allergic reactions are less specific. They can take a few hours to two days to appear. Digestive discomfort, constipation, reflux or diarrhoea are common signs, as is an unusual flare-up of your baby’s eczema.

Because eczema flare-ups can be triggered by many factors, if you suspect a delayed allergic reaction, it might be useful to try the food again a couple days later, before drawing any conclusion. It’s not advised to remove any foods from your baby’s diet to see if it helps with their eczema without consulting with your healthcare provider first.

When a baby suffers with severe or recurrent eczema, the first line of treatment is always appropriate skincare. When this is not sufficient, your healthcare provider will advise on testing and/or diet measures in addition to this.

Do I need to test my baby with eczema for food allergies before weaning?

While allergy testing is certainly indicated if your baby has presented with an immediate reaction after eating a food, it is not usually recommended to test eczema babies before weaning [2]. This is because they might be sensitised, due to their brittle skin, but not yet allergic. Testing would induce delays in introducing the food and so increase their risk of developing a real allergy. In some cases, for example if a baby has been avoiding a food for a long time, your doctor might want to test for an immune response before considering reintroduction.

If you’re ever unsure about when and how to introduce allergens when weaning, speak to your healthcare provider for guidance. 

[1] See blog, ‘Is your baby ready for weaning? Signs and considerations.’ 

[2] https://ifan.ie/wp-content/uploads/2017/11/20-questions-EczemaAllergy-DL-web.pdf

FAQs about eczema and food allergies

What is eczema?

Eczema (also called atopic eczema or atopic dermatitis) is a common skin condition that causes dry, itchy and inflamed skin because the skin’s protective barrier does not work properly.

What causes eczema in babies?

Eczema is caused by a combination of genetic and environmental factors that make the skin more sensitive, dry and prone to irritation.

Is eczema an allergy?

No, eczema is not an allergy. However, it is closely linked to allergies because babies with eczema can be more likely to develop food allergies.

Does eczema mean my baby will have food allergies?

No. Most babies with eczema do not develop food allergies. Only a small proportion, usually those with severe or early‑onset eczema, are affected.

When should babies with eczema start weaning?

Babies with eczema should start weaning between four and six months of age, as long as they are developmentally ready.

Should allergenic foods be avoided if my baby has eczema?

No. Early and regular introduction of allergenic foods such as egg, dairy, wheat and nuts helps reduce the risk of food allergies, even in babies with eczema.

Do babies with eczema need allergy testing before weaning?

Usually not. Allergy testing is only recommended if a baby has already had an immediate reaction to a food.

This content is for information purposes only and is not intended or implied to be a substitute for professional medical advice, diagnosis, or treatment. Always seek advice from your GP or an appropriate medical professional if you have concerns about your health, or before commencing a new healthcare regime. If you believe that you are experiencing a medical emergency call 999 / 112 or seek emergency assistance immediately. 

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