Excerpt from Chapter 3 of the book “Eczema! Cure It!”
Eczema! Foods the culprits!
The first comprehensive study that proved that food can cause eczema was done by David Atherton, in London, in the 1970s. He studied 36 children who had eczema. It was a thorough study with a design called a double-blind controlled crossover trial . The purpose was to see a diet excluding dairy and egg products would influence their eczema: 20 children completed all parts of the study. His results were startling: 14 children (70%) responded more favourably to the antigen-avoidance diet than to the control diet, whereas only one (5%) in the control diet group had a good response. Of interest, there was no correlation between a positive skin-prick test (SPT) to egg and cow milk antigen and response to the trial diet (see an explanation for this in the next chapter).
In later study, Guillet (1992) assessed over 250 children with eczema. He noted that increased severity of eczema in the younger patients was directly correlated with the presence of food allergy.
More recently, Werfel (2004) studied all of the allergy research that he could find and came to the conclusion: Multiple clinical studies have addressed the role of food allergy in eczema. These show that elimination of relevant food allergens can lead to improvement in skin symptoms; that repeat challenge can lead to redevelopment of symptoms; and that the disease can be partially prevented by eliminating highly allergenic foods from the diets of infants and possibly breastfeeding mothers.
Clearly, there is much written in the medical literature to prove that foods can cause eczema. Let s look at the details.
Foods in the womb
Once a baby has been conceived and is growing in the mother s womb, the baby gets exposed to fragments of food from mother s diet. The amniotic fluid (the watery liquid which surrounds the baby in the womb) contains these small amounts of food proteins that the mother has eaten. In the womb, the baby actually swallows this amniotic fluid.
It is thought that this early exposure to the mother s foods helps guide the child in later life about what is safe to eat. Also this early exposure should help the baby develop a tolerance to these foods. Unfortunately, sometimes this can go wrong. In susceptible babies from allergic families, this very early food exposure (especially to egg) can develop into early allergic food reactions. Subsequently, it can lead to eczema.
Food proteins in breast milk
Everyone knows that breast milk is the very best milk to feed a baby. Breast milk is the perfect milk for your growing baby. Importantly, breast milk contains tiny amounts of the foods that the mother eats. These food proteins help condition the baby to these tastes and flavours so that in the future, the introduction of foods will not be problematic (children are more likely to refuse foods that they haven t tasted through the mothers breast milk).
So when food proteins are looked for in breast milk, they can be found. Although the quantities of these foods are very small, it is clinically significant for the allergic child. Numerous medical studies show that babies can develop allergic symptoms from the food fragments of cow’s milk, egg, and peanut coming through the mother s breast milk. Other foods, especially gluten, can also cause trouble.
Amelia is 12 months old. She had positive skin prick tests to milk, egg and wheat. Her mum said:
To begin with, Amelia had dreadful allergies. She had eczema all over her face, so it looked like she had slapped cheeks all the time. She was just miserable with trying to scratch. We brought her to see Dr Ford and she got skin-prick tested. We discovered that she was allergic to dairy, peanuts and eggs.
So, I started taking those foods out of her diet well out of my diet mainly, because I was still breastfeeding her. Of course, I removed any traces of these foods from her diet as well whatever she was eating. Because at that stage she wouldn’t eat solids.
When I was still breastfeeding, her eczema improved it began to clear up almost straight away. But the trouble was that her weight gain wasn’t happening and she wasn’t eating any solids. Although I had taken these foods out of my diet, unfortunately, there must still have been traces of some trouble foods going through my breast milk.
She didn’t get fully better until she went onto the special low allergen milk (Neocate) not long after that she started eating solids. As soon as she was on this strict diet, her growth came back up. And best of all, now her skin is beautifully clear and we don t have to use any creams on her at all. She is also gaining in weight! Fantastic!
Colic and cow’s milk
Relief from colic has been observed in breast fed infants whose mothers have been put onto a diet free of both cow’s milk and dairy products. The baby s colic was found to return when the mother began eating dairy products again. These initial studies were done in 1978 by Jacobsson and Lindberg. These were open studies (mothers knew whether or not they were drinking cows milk) which showed that a third of colicky babies responded to their mothers going off dairy.
This work was subsequently strongly criticized, and so they repeated their research by doing double blind studies (they gave the mothers disguised drinks so that they did not know which days they were drinking cows milk). The mothers then observed the symptoms in their babies. By doing this more rigorous study, they confirmed their observations: that the colicky babies responded to dairy products. However this time round they found that a quarter (25%: one in four) of colicky babies got better when their mother went on a dairy free diet.
How do foods cause eczema
A wide number of foods can precipitate eczema. How does this happen These foods can trigger eczema through a number of different mechanisms:
- by immediate allergic reactions;
- by slow onset reactions;
- and by chemical irritation.
As there are a number of different mechanisms that can set off eczema, consequently, any single test is unlikely to identify all the foods that could be causing the problem. Therefore, solving the eczema puzzle needs to take into account many factors including the history of the illness, the patterns of eczema, allergy tests, blood tests results and response to treatment.
The next step is to look at the types of food reaction in more detail.
Immediate allergic reactions
Immediate reactions to foods are the easiest to identify. The medical term for immediate reactions is IgE-mediated reactions . This means that if a food is eaten, or even touches the skin, a reaction to that food will be seen within a few minutes.
However, if tiny amounts of this food are given on a regular basis (usually this happens through the breast milk), then an immediate reaction to that food is difficult to pick up.
The baby will start to get frequent rashes and then eczema will start to develop, especially on the face and cheeks. But because only tiny amounts of mother s food is getting into the baby every day, the offending food may not be immediately obvious. However, these types of food allergy can readily identified by skin-prick testing (see next chapter).
Slow-onset allergic reactions
Reactions to foods can also occur slowly. This means a reaction happening hours or even days after eating a food. These slow-onset adverse reactions are more difficult to identify. This is because there is not a close relationship between the time that the food is eaten and the time that the adverse reaction occurs. Also, under these slow-onset circumstances, skin prick tests are negative to the offending foods.
However, skin-patch testing has recently been demonstrated as a useful technique to reveal these delayed onset foods reactions. To do a patch-test, a small amount of the food in question is put onto the skin and covered with a special adhesive patch. It is left in place for 24 48 hours. The patch is then removed and skin is examined to see if an allergic reaction has taken place (this often provokes a patch of eczema at the test site).
The most common foods to cause delayed onset reaction are gluten and dairy. Blood tests can be done to look at the IgG-antibody levels of these two foods. High antibody levels suggest that the body s immune system is reacting to these foods. In turn, that means it is worthwhile giving a trial of a gluten-free and/or dairy free-diet if indicated by these blood tests.
It is my experience that for babies (under twelve months of age) that dairy is the most common slow-onset food reaction. When dairy is removed from their diet, often the eczema dramatically improves. For toddlers and older children, I have observed that gluten plays the most important role in their eczema (see Chapter 6).
Food chemical reactions
Every single thing that you put in your mouth is made up of chemicals. There are many thousands of different chemicals that get combined to make up the hundreds of varieties of foods that you eat. It is this vast assortment of chemical composition that gives your foods their characteristic colours, flavours and textures. Unfortunately, many of these natural food chemicals can also cause you food reactions.
Non-allergic food intolerance
Yes, naturally occurring food chemicals can spark off skin reactions. Some of these food chemicals have the ability to trigger the release of histamine from the allergy cells (mast cells) in the skin. This is a chemical irritation, rather than an allergic reaction. This can lead to histamine flare-ups of eczema especially around the mouth and cheeks.
Histamine is a substance that makes the skin very itchy. It is the substance that makes a mosquito bit itchy. The more the skin gets scratched, the worse the eczema becomes.
This chemical histamine release is usually seen as an immediate flare reaction around the mouth (called: non-immunological contact urticaria) to benzoic acid from citrus fruits in children (this is especially seen in children with atopic eczema).
Other food additives and colourings can also have this effect. Additives such as sulphites, salicylates, tartrazine and monosodium glutamate (MSG) are implicated in these flare-up reactions of urticaria and eczema.
Perhaps the best known type of chemical food reaction is called the oral-allergy-syndrome . This is a chemical reaction to foods which is felt in your mouth. It is found especially when the following foods are eaten fresh, raw and early in the season:
- Fruits: apple, peach, plum, nectarine, cherry.
- Vegetables: tomato, celery, carrot.
- Nuts: almond, hazel, walnut.
The oral allergy syndrome is characterized by a local itching or swelling in the lips, the mouth, the tongue and sometimes the throat. Some people have a burning sensation. This happens almost immediately (within minutes) after being in contact with the food.
The good news is that these irksome food chemicals (found in these fruits and vegetables) can be destroyed by heating. Consequently, for the relief of most sufferers, when these foods are cooked, these chemicals can no longer cause a reaction.
Irritant chemicals can be destroyed by cooking
Some children, as well as having this oral-allergy-syndrome, will also break out in eczema when exposed to these natural food chemicals. Such flare-ups can occur within minutes. This subsequent scratching can quickly make a mess of their skin.
The birch pollen connection
The mechanism behind the oral-allergy-syndrome reaction can be due to cross-reactivity to other pollen allergens (especially from birch pollen), or to food chemicals causing a release of histamine in the mouth and creating exactly the same symptoms of an allergic reaction.
Many other chemicals and irritants can cause eczema flare-ups when in direct contact with the skin: for instance washing powders, wool and fabrics. These aggravators need to be identified before the eczema skin can fully heal.