Many children with eczema also have food allergies. Although in most cases food allergies are not the primary cause of eczema they can make it much worse.
Food allergies occur when the immune system has incorrectly tagged a protein in a food as a pathogen (intruder). This may be caused by the protein penetrating the skins moisture barrier which is compromised in children with eczema. As the food protein has reached parts of the body that it should not, the immune system tags it as an intruder. The other theory is that the protein has penetrated the bowel wall due to permeable bowel lining (leaky gut syndrome) although this theory is disputed by many in the medical world. Either way, once a protein has been tagged as an intruder the immune system will produce a histamine response whenever that protein is eaten.The histamine response can cause the skin to itch which leads to scratching and worsening of the eczema.
There are two types of food allergy response. Ige and T cell. Ige (Imunnoglobulin E) is an antibody that is created in response to the presence of a pathogen or allergen (the food protein in allergic children).
With Ige responses the allergic response is very quick. Scratching can start in as little as 10 minutes. With T cell allergies it can be many hours or even days before the scratching starts. This makes them much harder to spot.
If you suspect your child has a food allergy then keep a food diary to try and find the triggers. Common triggers are milk, egg, nuts, soy, and fish.
When you have some suspects ask for a RAST test. This tests for the Ige antibody in response to the foods that you have identified as suspects. They will not test all foods due to the expense and endless list of possible foods so you need to identify the suspects first.
Do not be tempted by internet companies offering Igg tests. Despite these companies claims,most of the major national allergy associations of the world advise that they are unreliable. Igg tests often identify a huge list of allergens which leads to parents removing dozens of foods from their childs diet which can lead to nutrient deficiencies. This scatter gun approach may by luck lead to removal of the offending food allergen but this is less than ideal.
T cell allergies are less easy to identify and only food elimination diets will identify them. Try to take advice from a dietician before you do this.
Many parents who identify the food triggers see an improvement in their childs eczema. However, just as many do not which can be heartbreaking. There may be several reasons for this e.g
- There are other food triggers that have not yet been identified
- There are still environmental triggers (dust mites, cat dander, washing powder etc.
- The eczema is being maintained by the bacteria staphlococcus aureous. (See my blog Staph Wars)
The good news is that many children grow out of food allergies and the foods can be gradually introduced back into the diet using the ladder technique. Here is an example of a milk ladder which can be downloaded from the cows milk protein allergy website