The relationship between eczema and food allergy is one of the most common questions I am asked by parents. The short answer is: yes, food allergy can contribute to eczema in some children — but it is not the cause of eczema in most children. Understanding when food allergy is relevant, and when it is not, is important to avoid unnecessary dietary restriction.
The Eczema–Allergy Connection
Eczema (atopic dermatitis) and food allergy are both part of the "atopic march" — the tendency for allergic conditions to develop in sequence in susceptible individuals. Children with eczema are at higher risk of developing food allergy, asthma and hay fever. This is because eczema involves a disrupted skin barrier, which allows allergens to penetrate the skin and sensitise the immune system.
Research has shown that food allergy is more common in children with eczema than in the general population — particularly in infants with early-onset, moderate-to-severe eczema. However, this does not mean that food allergy is causing the eczema in every case.
When Is Food Allergy Likely to Be Contributing to Eczema?
Food allergy is more likely to be contributing to eczema when:
- Eczema starts in the first year of life and is moderate to severe
- Eczema is difficult to control despite good topical treatment (emollients and topical steroids)
- There is a clear temporal relationship between eating a food and eczema flares
- There are other allergic symptoms alongside eczema (immediate reactions such as hives or vomiting after eating)
- There is a strong family history of allergy
When Is Food Allergy Unlikely to Be the Cause?
Food allergy is less likely to be driving eczema when:
- Eczema starts after the age of 2–3 years
- Eczema is mild and well controlled with standard treatment
- There is no clear link between eating specific foods and eczema flares
- Eczema improves with good skin care alone
Should My Child with Eczema Have Allergy Testing?
Routine allergy testing is not recommended for all children with eczema. Testing is most useful in children with moderate-to-severe eczema that started in infancy and is not adequately controlled with standard treatment. It is also useful when there is a clinical suspicion of food allergy based on the history.
I would caution against testing all children with eczema indiscriminately. Allergy tests in the context of eczema can produce positive results that are not clinically relevant — leading to unnecessary dietary restriction that can affect a child's growth and nutritional status, and cause significant anxiety for families.
What Happens at an Allergy Assessment for Eczema?
At Belfast Children's Allergy Clinic, I will take a detailed history of your child's eczema — when it started, how severe it is, what treatments have been tried, and whether there is any link with specific foods. Based on this, I will advise whether allergy testing is appropriate and, if so, which tests to perform.
If food allergy is confirmed as a trigger, I will provide dietary advice and refer to a paediatric dietician if needed. I will also optimise your child's eczema treatment plan.
See also: Eczema and Allergy in Children
Dr Mugilan Anandarajan, Consultant Paediatrician (FRCPCH, MD). Also see: belfastallergyclinic.com | belfastchildrensclinic.com