Allergy vs. intolerance

Both exhibit a few similar symptoms, and it takes a professional to determine the subtle differences, writes VICENTE DE VEYRA III

FOR SO LONG, Nina would get a rash after every meal, but she would take it for granted. She can’t remember when it all started, but when finally she decides to take her long-ignored problem to the doctor, she was in for a surprise. Advised to see an allergologist, Nina had to undergo several sessions only to learn that she has an allergic reaction to rice. An Asian allergic to rice! It took 28 injections to fix her problem. Clearly, Nina’s case was a long-present food allergy. Or could it have been food intolerance?

An abnormal response to something that has been ingested, a food allergy starts as a specific reaction in the immune system that is then expressed through certain symptoms, often characteristic. Other kinds of reactions to foods that are not food allergies include food intolerances (such as lactose or milk intolerance), food poisoning, and toxic reactions.

Food intolerance is also an abnormal response to food, with symptoms that resemble those of a food allergy. And unbeknownst to many, food intolerance is far more common than food allergy. It occurs in a variety of diseases, triggered by various bodily mechanisms besides the immunological reaction responsible for food allergy.

Food allergy: an antibody’s misreading

When the body’s immune system confuses a food protein for a harmful element, a food allergy can be said to be in progress. A body’s immunoglobulin E antibody may mark a food protein that is resisting digestion as an invader and signal this to the body’s immune system. The immune system would then transmit white blood cells to assault the invader, activating thus an allergic reaction. People who have food allergies must identify these reactions and their stimuli in order to prevent their recurrence because, although usually just mild and not severe, they can cause another major illness to occur and can even be fatal.

Food allergy reactions that may be anywhere between mild and severe, may manifest either as dermatitis or gastrointestinal and respiratory distress, or life-threatening biphasic anaphylaxis or vasodilation that would require emergency intervention. People with allergies commonly avoid contact with the problem food, although some medications may put off or reduce those same allergic reactions. There is no quick cure, by the way.

Asian cases: unique little details

In a study published in Asia Pacific Allergy journal early this year, authors Alison Joanne Lee, Meera Thalayasingam and Bee Wah Lee conclude that although the prevalence of food allergy in Asia is increasing, with immune disorders of the gut such as eosinophilic oesophagitis making a parallel rise, it is still relatively lower than those occurring in urbanised Western populations. Especially lower has been the occurrence of peanut and tree nut allergies. The authors write, “These observed differences in prevalence are intriguing and deserve further study, since an affluent lifestyle is no longer an acceptable explanation as many urban regions of Asia are developed and affluent.”

The study’s authors also point to the pattern of food allergens different from those in the West (say, shellfish as the most common food allergen from Asia, in part due to the abundance of seafood in this region). They saw this patternAir Jordan