We all know that eczema shows up on the skin, but it is actually considered a disorder of the immune system, and involves defects in the skin barrier, skin dryness and inflammation¹. Food allergies also involve the immune system, so it might not come as a surprise that around 30% of children with eczema and a family history of allergies will also develop a food allergy before the age of five (compared with only 10% in the general population)1.
The link between eczema and food allergy
While there is undoubtedly a link between eczema and food allergies, and food allergy may trigger eczema flare ups in some people, it is not the cause². Certain food allergies and eczema are sometimes grouped in the same family with asthma and hay fever, which are related because they all typically involve increased production of immunoglobulin E (IgE) antibodies in response to low amounts of common allergens2. As a result, they often occur in tandem.
Diagnosing food allergies with eczema
Food allergies can be potentially serious, with a risk of anaphylaxis in extreme cases, so it's important to discuss any concerns with your doctor. Specialists can investigate the cause of a suspected allergy through skin prick tests or serum specific IgE tests2. Common food allergens may be considered as possible triggers for eczema include cow's milk, eggs, wheat, soy and peanuts2.
Food exclusion diets
It may be tempting to simply try eliminating certain foods from your/your child's diet, but you should always consult a clinical immunology/allergy specialist first. While it can be an option if best practice topical therapy proves unsuccessful on its own, excluding common foods from the diet without suitable replacement can lead to malnutrition and may affect normal growth1.