Category Archives: Food Allergy
Allergies are a serious concern and unfortunately, allergens come in all forms. Peanuts, prawns, pollen, penicillin. Even sweat and semen. Conventionally, we are told to avoid allergens, but a new study from the UK suggests we should instead tolerate allergens instead of avoiding them. Scientists found that eating peanuts early in life can prevent the development of peanut allergies later. We speak to The Allergist to understand the implication of this defining study and allergies in general.
The interview was done at BFM radio. Please feel free to click on link below:
We are all very excited about the recently published study from the New England Journal of Medicine that looked at early introduction of Peanut to at risk children (these are children with severe eczema, who are at risk of developing peanut allergy). What this study found was that avoidance of peanut did not prevent peanut allergy. In fact, children that were given peanut had a 86% reduction in peanut allergy compared to those that practised avoidance.
Overall, studies are now pointing that the allergen avoidance strategy that were employed in the past did not prevent allergy. We are now understanding that the immune system needs to gain what is known as immune tolerance in order to not develop allergies.
Do note that what we are finding out is that avoidance does not prevent allergy but once allergy has developed, avoidance is the best management strategy.
Please see a qualified Allergist if you and your family have a strong family history for allergies and want to know more about allergy prevention strategies.
ALCAT is a test marketed to test for food allergy or food intolerance. It basically measures changes in the white-cell diameter after laboratory challenge to numerous different allergens or substances. Unfortunately, this method has not been scientifically validated and has no concrete published evidence. When blinded samples were sent, the test demonstrated no reproducibility (This means when the same sample were sent twice, the results came out completely different even though they were from the same sample).
The test also could not demonstrate food allergy or intolerance in patients that had true diagnosis of food allergy or intolerance. It is important to get proper evaluation by a trained and certified Allergist for evaluation of your food allergy.
Below is the statement position by the Australasian Society of Clinical Immunology and Allergy:
Cytotoxic testing (also known as Bryans’ or ALCAT testing)
Use: Diagnosis of food sensitivity / allergy.
Method: A suspension of patient white cells is incubated with dried food extracts on a microscope slide. Changes in the appearance and movement of cells are interpreted as representing a sensitivity or “allergy” to that food. The ALCAT test is a variation, whereby a mixture of blood and food extracts is analysed in an automated Coulter counter.
Comment: These results have been shown to not be reproducible, give different results when duplicate samples are analysed blindly, don’t correlate with those from conventional testing, and “diagnose” food hypersensitivity in subjects with conditions where food allergy is not considered to play a pathogenic role.
Below is a link to a New York Times article:
For many years, there had been no available treatment for food allergies. The management for food allergies consists of proper evaluation by an Allergist to determine the food trigger and avoidance. Portable epinephrine (Epipen) was used for any reaction due to accidental ingestion of allergic foods.
Immunotherapy for food allergy is now under investigation as a possible treatment for food allergy. It is important to understand that this form of treatment is for IgE-mediated food allergy. At this time, we are not sure if food allergy can be cured by this method. However, successful immunotherapy could at least reduce the chance for a fatal allergic reaction and in some cases allow the previously allergic food to be eaten. It is important to understand that this is still a new method for food allergy management and there are still a lot of unknowns.
Currently there are two methods of immunotherapy for food allergy, one is oral immunotherapy and the other is sublingual. There are subtle differences between the two methods and each has its advantages and disadvantages.
The Allergist can properly evaluate your food allergy and discuss management options for your food allergy.
Food protein induced enterocolitis syndrome (FPIES) typically affects infants and young children, and causes symptoms of vomiting and bloody diarrhea that leads to dehydration and shock after the consumption of certain foods.
FPIES may be confused with food allergies, since the reaction occurs after the consumption of certain foods. However FPIES is not an IgE mediated food allergy, as such allergy blood tests that measure specific IgE towards the food is not helpful.
Symptoms of FPIES are often delayed, usually within a few hours of eating the culprit food. The patient usually presents with vomiting and diarrhea that rapidly progress to dehydration and shock in 15-20% of patients. The child usually presents to the emergency appearing lethargic and is usually diagnosed as septic. Bloody stools can be the initial manifestation of FPIES although this is more commonly seen in Food protein induced protocolitis syndrome. The two most common culprit foods are cow milk and soy.
Although FPIES is a clinical diagnosis, the nonspecific symptoms and lack of definitive diagnostic tests may also contribute to a delay in diagnosis. Management of FPIES consists of removing the offending food from the diet. For infants, exclusively breastfeeding can be protective. Extensively hydrolyzed casein formulas are recommended for infants that cannot be breast-fed. Oral food challenge can be done to determine when the child has outgrown FPIES to the trigger food; this should be done with physician supervision and preferably in a hospital setting.