Eczema and food allergies: The practicalities of elimination diets

Food allergies and dietary eczema triggers may be diagnosed with a trial elimination diet. This is where the suspected food is removed from your child’s diet (or yours, if you are breastfeeding) for two to four weeks before being reintroduced. In most cases, if a given food is a indeed trigger for your child’s eczema, it will improve within 3-4 days of removing that food. However, it’s important to check that any conclusions with a food challenge.

Before you read any further: Elimination diets should only be conducted with medical supervision to ensure that you child is not missing out on vital nutrients. For example iodine, found in eggs and dairy products, is important in children’s brain development.

• Keeping a food and symptom diary before trying an elimination diet should help to identify the most likely food triggers for your child’s eczema.
• There are 2 ways of doing an elimination diet experiment: eliminate one food at a time; or, eliminate all suspected foods at the same time and then add them back in one at a time
• It’s important to remain dispassionate and avoid wishful thinking when evaluating changes in symptoms and test any conclusions with a food challenge or formal allergy test. Keep in mind that research has found that only 10% of children with food allergy symptoms (eczema, reflux, wheezing and nasty nappies) have genuine food allergies.

Elimination diets – the practicalities

Before you start:

• You can increase the chances of finding problem foods, by keeping a food and symptom diary for a few weeks. Note down what your child (or you) eat and when your child’s eczema flares and look for any patterns. You can read more about tracking down triggers this way here.
• The most common allergens are dairy products, soy and eggs. These will typically cause more problems than just eczema including colic, reflux, wheezing and nasty nappies.
• Tomatoes, citrus fruit and strawberries (especially raw) are also common triggers for eczema.
• Once you have a short list of suspected problem foods you can start to investigate whether or on they are causing flare-ups

There are 2 main ways of doing an elimination diet experiment.

Eliminate one food type at a time:

• Take out one food type at a time. Our beginners guides dairy and egg free cooking may be helpful.
• Give each food 2-4 weeks before deciding whether it is causing your child’s symptoms. It’s really important to be dispassionate when evaluating your child’s symptoms and avoid any wishful thinking. If an improvement isn’t really obvious, that food is unlikely to be trigger for your child’s eczema.
• If the symptoms improve, may you found the problem. In most cases, symptoms will improve with 3-4 days of avoidance. If you are breast feeding, the food will clear from your milk in a few days, but your baby’s eczema may take a little longer to heal.
• If the symptoms don’t improve in 2-4 weeks they are probably not related to the eliminated food. Add it back into your diet and move on to the next candidate.
• Check your conclusions with a challenge test.

Eliminate all at once:

• Take out all cow’s milk products, soy and eggs from your diet.
• Wait 2-4 weeks to see if your child’s symptoms improve. As above, in most cases symptoms will improve in 3-4 days. If you are breast feeding, the food will clear from your milk in a few days, but your baby’s skin may take longer to heal.
• If symptoms do improve, introduce one new type of food at a time, generally the one that you find hardest to cook without. If symptoms return, you have found a possible trigger. Remove that food from your child’s diet again, wait for symptoms to improve then add back the next food on the list.
• If symptoms don’t improve in 4 weeks they are probably not food related and you should back to your regular diet.
• As above, remember check your conclusions with a challenge test.

While the ‘all at once’ approach may appear to be the fastest way to alleviate your child’s symptoms, eliminating multiple foods at the same time is complicated and likely to require a lot of thought. Given that, in all likelihood, you aren’t getting great amounts of sleep while your child’s skin is sore and that any slip-ups will invalidate the whole elimination experiment, we suggest the one at a time approach. This also reduces the risk that an elimination diet has to overall levels of nutrition.  

Food challenges:

It’s vital to check that any conclusions with a regular food challenge.

• Serve up a good-sized portion of the suspected food, and monitor symptoms.
• If food is a trigger, symptoms are likely to worsen within 12-24 hours.
• Remember that stress is also a trigger for eczema so ideally don’t make a big thing of food challenges.
• Many children with confirmed food allergies will grow out of them in time, so it’s important to test regularly for continued sensitivity.

Something to think about

Research has found that only 10% of children with food type symptoms (eczema, colic, reflux, wheezing and nasty nappies) have a genuine food allergy¹, so it’s really important for a food allergy diagnosis to be confirmed by an appropriate medical professional. Restricting your child’s diet not only makes life much harder for you but, without expert advice, may also impact on their long term growth and development. In addition, there are concerns avoiding allergens for long periods can result in the development of dangerous allergic reactions in later life². Restrictive diets have also been shown to have a negative impact on a child’s relationship with food in long term³. It is worth considering whether it may be better to live with manageable eczema than to restrict your child’s diet.

Our sources

1. Martín-Muñoz, MF, et al. “Food Allergy in Breastfeeding Babies. Hidden Allergens in Human Milk.” European Annals of Allergy and Clinical Immunology, U.S. National Library of Medicine, July 2016, https://pubmed.ncbi.nlm.nih.gov/27425167/
2. Nachshon, L, et al. “Food Allergy to Previously Tolerated Foods: Course and Patient Characteristics.” Annals of Allergy, Asthma, & Immunology, U.S. National Library of Medicine, July 2018, https://pubmed.ncbi.nlm.nih.gov/29684569/
3. Gray, PE, et al. “Salicylate Elimination Diets in Children: Is Food Restriction Supported by the Evidence?” The Medical Journal of Australia, U.S. National Library of Medicine, June 2013, https://pubmed.ncbi.nlm.nih.gov/23919705/