Tag Archives: food allergy

Even tiny whiff enough to trigger allergic reaction

A review of food reactions in children from inhalation was recently published in an issue of Allergy and Asthma Proceedings.

As an introduction, the authors remind readers we are able to smell foods because of tiny aerosolized particles of food. In some children, even this tiny amount of exposure can lead to allergic symptoms.

The foods most commonly implicated in this mischief are: fish, nuts, legumes, grains and cow milk.

Up to 10 percent of children allergic to fish will have some type of allergic response to seafood odors or fumes. Typically, this is eye itching, sneezing or wheezing.

Of interest, shellfish were much less likely to cause inhalation problems than “swimming” fish.

The incidence of airborne nut allergy was smaller with three percent of children with tree nut allergy reacting to the smell, and one percent of peanut-allergic children reacting. (Even though peanut is a legume, it was studied in the nut category because there are so many children with peanut allergy.)

Again, common symptoms seen were eye itch, sneezing and wheezing. But some children suffer hives and even anaphylaxis from nut odor inhalation.

The most common legumes to cause inhalation allergy are soy, chick peas, peanut-like lupines and green beans. The spectrum of symptoms: eye itch, sneezing and wheezing, but also intense itching in the mouth and throat in some children.

The cereal grains most likely to cause problems are rice, buckwheat and wheat. Buckwheat is more common a cause than expected because many children have ongoing exposure from buckwheat chaff being used in stuffed animals.

And while cow milk is a common cause for inhalation allergy, some children are sensitized from powdered formulas being mixed in their presence.

Also, as mentioned in a previous newsletter, some asthma inhalers contain small amounts of milk protein as a stabilizer.

Few victims, but plenty of chances to ingest

Heads up. This article is truly only intended for a very, very select group of individuals with severe food allergy. It addresses a very special situation when foods are found as an excipient (non-active ingredient) in a medication.

Excipients are added in manufacturing to protect, support or enhance stability or bioavailabilty of an active ingredient.

The amount of food found as an excipient is truly miniscule, and therefore, 99.99-plus percent of people actually allergic to that given food would not – repeat NOT – be affected by the tiny amount found in the medicine.

Some medicines that contain trace amounts of egg include: Interferon, some probiotics, vaccines against flu, measles-mumps-rubella (MMR), rabies and yellow fever; Propofol, Ibuprofen, some multi-vitamins, Rosiglitazone and diphenhydramine.

Tiny amounts of fish protamine are found in NHP insulin.

Gelatin is found in many capsules and tablets, and in some suppositories and nicotine chewing gum. Vaccines for flu, Japanese encephalitis, MMR, rabies, tick-borne encephalitis, typhoid, varicella, yellow fever and zoster also contain it.

Milk has four allergy-causing proteins: Casamino acids are found in vaccines (DTaP, meningococcal pneumococcal, Td). Casein is found in Cefditoren, Miconazole, some probiotics and vaccines (TDaP, typhoid). Lactalbumin is found in the oral polio vaccine. And lactose is found in many tablets, capsules and granules. It is also in some asthma inhalers: Foradil, Advair, Flovent, Ventolin, Pulmicort, Spiriva, Symbicort and Asmanex.

Peanut oil is found in dimercaprol injection, progesterone capsules and valproric acid capsules.

Pine nut resin is found in fluoride tooth varnish.

Mother’s milk, delayed solids: Food allergy prevention standards, but we can always learn from new data

 This month’s issue of the Journal of Allergy and Clinical Immunology has a symposium on food allergy.

Until recently it has been recommended that a good strategy to reduce risk of children developing food allergy was to promote exclusive nursing as a food source, to have the mother avoid highly allergenic foods and to delay weaning with introduction of solid foods.

However, despite the implementation of this approach in a number of countries in Asia, Europe and North and South America, there has been no reduction in the incidence of food allergy. The recommendations were made based on individual facts that are true, but that unfortunately do not lead to the desired outcome.

It is definitely true that mother’s milk is the best and most complete of infant nutrition. It is also true that mother’s milk contains a host of proteins and immune globulins that provide protective immunity to the infant. It is also true that early exposure to foods other than mother’s milk can lead to the development of food allergy.

From all these facts it was assumed the feeding recommendations also would be the best course to follow.

Once the potential benefit of this dietary approach was actually studied however, it was quickly learned that it did not provide the desired results. As it turns out a crucial fact that was previously unknown makes a pivotal difference.

If infants have early exposure to non-breast milk foods through skin contact, this is what leads to allergic sensitization. This has been born out in animal model research. Paradoxically, the food allergy development through skin contact can actually be prevented by early oral exposure to the food, e.g., from parents’ hands, kisses, etc. A good example of this phenomenon has actually been recognized for quite some time and it has to do with nickel allergy.

If a child’s first exposure to nickel is from pierced ears (skin exposure), there is up to a 40 percent chance of the child developing nickel allergy. If, on the other hand the child has oral nickel exposure from placement of orthodontic braces prior to ear piercing, the risk of nickel allergy is almost zero.

At this point in time the American Academy of Allergy has no specific recommendation. There are, however, numerous randomized controlled studies that are being conducted comparing the early exposure to foods such as peanut, milk, wheat and egg versus strict avoidance of these foods. Such studies will lead to a new evidence-based recommendation on how to prevent food allergy.

Vaccine Research addresses serious worldwide uptick in food allergy

Another part of the Journal of Allergy and Clinical Immunology’s food allergy symposium addressed European research on food vaccines. Impetus for this research is the worldwide increase in food allergy and also the increasing frequency of anaphylactic shock from food allergy.

Since vaccine therapy has proven successful in treating respiratory allergies and has also worked to prevent recurrent anaphylaxis from insects, it stands to reason that it could help eliminate food allergy and prevent food-related anaphylaxis.

Four types of vaccines for food allergy have been studied in Europe (and other countries): oral, sublingual, epicutaneous and subcutaneous.

All of these methods have proven to be of some benefit. Unfortunately, the ones that lead to the best improvement seem to have more side effects. Between the two ingestion vaccines (immunotherapy), oral immunotherapy leads to better reduction in allergy than sublingual.

The oral route commonly leads to GI side effects such as heartburn, nausea, vomiting, cramps and diarrhea. The sublingual route was much less likely to cause these symptoms, but did lead to itching and swelling in the mouth. Epinephrine shots had to be given twice as often for reactions in the oral group as compared to the sublingual group.

But patients who were successfully treated from both groups were able to ingest the implicated food – such as peanut – without going into allergic shock.

Subcutaneous immunotherapy, which is how traditional allergy shots are given, was more effective than epicutaneous immunotherapy. But once again, the more effective format led to more frequent vaccine reactions and to greater need for epinephrine to treat some of the reactions. When either of these techniques was successful, it again allowed the patient to safely ingest the offending food.

The European study group is conducting new and longer studies of these various forms of immunotherapy. The studies will include children, adolescents and adults. They also are adding studies to compare the use of pharmaceutical-grade food extracts versus the use of the entire native food as a vaccine substrate to see which works better and is safer.

New guidelines can help diagnose food allergies

The American Academy of Allergy, Asthma and Immunology (AAAAI) has just released guidelines for diagnosing and managing food allergies. These guidelines were conceived because of a lack of uniformity among physicians in testing and treating food allergy.

Frequently, pediatricians, family physicians and internists will order tests for food allergy. It is especially important that non-allergist physicians – as well as allergists – have a standard guideline for handling food allergy issues.

The AAAAI starts by pointing out that food allergy is common, but that many persons also have adverse reactions to foods that are non-allergic in origin. Proper testing/evaluation can separate these disparate conditions.

The AAAAI notes that the most common food allergens are milk, eggs, peanuts, tree nuts, shellfish, wheat and soy. The natural tendency is for an individual to outgrow the allergy. This is true for most foods, and studies have found that 80 percent of children outgrow their food allergies. This, however, is not true for peanut, tree nut and shellfish, where statistics show that only 20 percent of children outgrow these allergies.

The AAAAI makes a strong point that a positive test does not necessarily mean the patient has a true allergy to the food. What is also needed is a relevant history of prior reaction to the tested food or a confirmation of the test by an oral challenge. Oral challenges can be done at home following an elimination period. In cases of severe anaphylactic food allergies, food challenges may be done in an allergist’s office or in a hospital.

The most sensitive mechanism for testing is skin testing which measures IgE levels to the food. The RAST test, ELISA or Immunocap are blood tests for IgE.

Some labs offer a non-standard IgG food test which has no relevant value in diagnosing food allergy.