The Tuesday Science Times recently featured an article by Jane Brody. She is the finest science journalist in the country and I have followed her articles before there was even a Science Times section. Her article today is Have a Food Allergy? It’s Time to Recheck. The article references the recent National Institutes of Health Guidelines for doctors defining, diagnosing and treating food allergies. Unfortunately, ” The Guidelines”, are mainly about too many people – children and adults – being diagnosed with food allergies by various means, who most likely don’t have a food allergy.
Allergy testing can confirm a diagnosis, not make one
They mention that skin prick tests and blood tests can be misleading. I do agree any test can be misinterpreted if the reviewer is not experienced in diagnosing the medical condition in question, and that testing should clarify or confirm a diagnosis - not make a diagnosis. However, I’m also concerned that the report didn’t address issues I mentioned in my prior post on the dangers of not adequately preparing for a serious food allergy.
Making the connection with meals
My experience has been that patients who suspect they have food allergies as the cause of their symptoms need a very careful history: noting when the possible food reaction occurs in relation to meals, what is the exact reaction (skin, respiratory or, most likely, gastrointestinal) and what foods are safe to eat. There are many patients that have food related reactions that can be labeled adverse reactions because they don’t always cause the same problem, but patients who are aware can see a pattern.
The most common food intolerance
The classic food intolerance is lactose intolerance, which is the result of lacking adequate enzymes to digest milk products. This can develop after many years of drinking milk. We can lose the amount of enzyme in our bodies that we once produced. The other classic intolerance is to wheat, but is more serious in those patients with a diagnosis of Celiac disease. This is an autoimmune disease triggered by the ingestion of wheat products. The danger with Celiac disease from patients I have seen is that they don’t always recognize that wheat products like bread are making them sick. They just don’t feel well and many times can be anemic or have rashes or arthritis. There are blood tests available that can help establish the diagnosis. A blood test called anti-tissue transglutaminase IgA and anti-endomyosomal IgA antibodies are the non-invasive tests to ask for.
The most important question you have to ask yourself, or as a parent regarding your child is: does there seem to be a relationship between the symptoms and eating meals. Patients without food allergies have symptoms even when they don’t eat. A food allergy in most cases occurs within minutes or up to an hour after eating the allergic food. I strongly believe that if your symptoms have a temporal relationship to your meals or snacks then food allergy testing can be beneficial. The studies cite that only a few foods cause most of the food allergies: milk, eggs, peanuts, tree nuts, soy, shellfish and regular fish. In reality, there are many foods that can cause a serious food allergy. I’ve had a patient that is allergic to chocolate- she can’t even go into a room where someone has been eating a chocolate candy bar. I have a patient that is also so allergic to tuna that she couldn’t go into a restaurant because the smell of tuna gave her an asthma attack. These are the real food allergies - and testing and educating my patients how to be prepared to treat a reaction is my job!
For serious food allergies, you don’t need to challenge the patient with the food – that could be dangerous. There are new blood tests that measure the specific proteins a person may be allergic to which is helpful in assessing how serious the food allergy is, and if it must be avoided. It’s called Component testing and right now it is the best test to assess the potential danger in a peanut allergic patient. The peanut has 9 different proteins that can be tested, and one of them has been identified with severe peanut reactions called Ara h 2. This test can be specially ordered by your doctor from PIRL labs in Michigan.
The future is promising
The treatment for food allergies right now is frustrating – just avoid eating the food. However, in my book, Dr. Dean Mitchell’s Allergy and Asthma Solution, I devote a whole chapter to food allergies and mention the different treatments being evaluated in clinical trials now. The future does look promising, but for now, if you think you have a food allergy, please see an allergist. If you have a food allergy, always have your EpiPen on hand.