Allergies

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It has been suggested that short gut kids may be at greater risk for food allergies, due to the increased permeability of the intestine to the proteins in food that trigger allergies. Please share your own experiences here so other short gut families can have a sense of what might happen, and what can be done about it.

Warning To Parents: If you have a family history of food allergies (or even other milder forms of allergy), and you have a short-gut baby, you may need to be extra careful in what you feed your baby (and what Mom is eating if she is nursing or otherwise providing breastmilk).

Contents

Basic Allergy Info

In addition to consulting with your doctor and a professional allergist, a number of websites provide valuable official information:

Here are some of the most important points:

  • Food allergies are caused by protein, not by oil, fat, or sugar, so for example a soy oil can be non-allergenic for someone who has a general allergy to soy. However, small amounts of protein can make it into any of these extracts, so the quality and manufacturing process etc all matter.
  • Also, although the situation is getting better with recent improvements in labeling, it is often hard to know what foods contain which allergens. Many websites provide extensive lists of obscure ingredients that contain common allergens.
  • There are 3 main ways of testing:
    • Skin test: small drops of allergens are placed on the skin, and it is pricked to let it get under the skin a bit, and if a bump or welt occurs, that indicates an allergy. If this shows a negative result, it is 95% likely to be accurate. A positive result is less accurate (don't know the exact number). What will the skin test be like for my child?
    • IgE RAST or CAP-RAST: this is a blood test that measures IgE antibody to different food proteins. The results are given in levels from 1-5 -- only higher levels (4-5) are more reliable indicators. As with the skin test, a negative result is accurate, but positive is hard to interpret (see Max Munakata's story below). Also, it is important to measure total IgE overall, because highly elevated levels (above 1000 or more) can lead to false positives.
    • Oral Challenge: this is the "definitive but dangerous" test: increasing amounts of a given food are given to see if a reaction occurs. This should only be done under the supervision of a doctor with epinepherine available should a bad anaphylactic reaction occurs.
  • If there are positive but ambiguous results on one type of test, getting the other kind may help explain what is going on. Because only a negative result is interpretable, if you get a negative on either test, that is valuable information. Similarly, if you get a positive on both tests, then that might increase your confidence that there is a problem.
  • There is no cure except avoiding the problem foods/proteins. For many of the most common allergens in young kids (eggs, milk, soy) most kids will outgrow them by age 5 or so. Other common allergens including peanut, nut, fish, and shellfish are not typically outgrown.
  • Some foods can be sensitizing at early stages of development (generally the "top 10" bad guys, including eggs, milk, soy, etc), meaning that eating them makes the allergy worse. However, at some later point, further consumption can actually be desensitizing. As with many things in the field of allergies, this is quite fuzzy and hard to pin down.
  • Early on, sensitization may occur through mother's breast milk, so those with a family history of food allergies might want to be careful to avoid some of the most common allergens.
  • Beware of cross-reactions with some common early foods. Peas in particular are one of the "first foods" in baby food selections, but they can lead to cross reactions with peanut, and sensitize a latent peanut allergy! Also, banana and mango are part of the rubber tree family and can sensitize a latex allergy.

Short-gut Specific Issues

  • Many medications and IV nutrition (specifically lipid formulations, including Omegaven) have egg and soy-derived ingredients, which act as emulsifiers to keep things from separating out (oil and water don't mix, but emulsifiers overcome that problem). Specifically, egg lecithin and soy lecithin, which are phosphatides, are commonly present. In the case of egg, this is derived from the yolk, whereas the common allergy is to the protein found in the whites. Furthermore, these are highly purified and typically do not contain much of the protein that causes allergies. So, in general, it seems that kids with egg allergies tolerate these meds just fine (true for Max Munakata, story below, who has a strong egg allergy but is on Omegaven, which has egg phosphatide). However, apparently there are rare cases of allergic reactions, so this is something you want to look out for.

Specific Patient Stories

Max Munakata

Max had eczema (itchy red skin) from early on. We attributed it to getting his mother's skin. Then we noticed as we started feeding him that he seemed to get worse some times, and occasionally had strong flushing and puffy face reactions. When we finally got allergy testing, we found that he is strongly allergic to egg, cow's milk, and peas (5's on the RAST and big welts on the skin test). It is possible that he would have developed these allergies regardless of what we did, whenever he was exposed to these foods. Given that he had never eaten eggs or milk, these must have been sensitized through breastmilk. The peas were from baby food which we eagerly and ignorantly gave him early on, along with carrot, sweet potato, and other such items. Although his first skin test was negative to peanut, his later one was positive, so it seems that peas cross-reacted with a latent sensitivity to peanut.

So far, this is pretty "normal" for a food allergy in a kid. However, Max has some weird results that may be attributable to his short gut. The main one is that his RAST test showed positive results to a large number of different foods, mostly in the 2-3 range. However, skin tests for most of those foods were negative! So, the key point as mentioned above is to get both kinds of tests because negative results are much easier to interpret, and there may be factors, perhaps more prevalent in short gut, that lead to an artificial elevation in IgE values without actually having a true allergic reaction. Our current theory is that his increased gut permeability and liver disease (possibly aggravated by the zantac that reduces the acidity in the stomach and thus reduces the breakdown of proteins) led to greater penetration of protein through his gut wall and into the enteric immune system, producing elevated IgE, but somehow not enough in general to lead to a full immune activation.

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