This is part 3 of a 3-part series of blogs on allergies. Read the first blog here: http://parentedge.in/all-about-allergies-part-1/ and the second part here: http://parentedge.in/all-about-allergies-part-2-indoor-and-outdoor-allergens/.
Not all adverse reactions to food and drugs are allergies; that is, they are all not a hypersensitive upheaval of the body’s immune system. Studies suggest that only around 8% of children under three have diagnosed food allergies (the prevalence in adults is 1.5%) while 25% of parents believe that their children have them. However, food allergy is a concern because it is a major contributor to life-threatening anaphylaxis, as are drugs. The good news, however, is that the likely offenders are few. It is also essential to know that food allergies run in atopic families. So those with atopic dermatitis or asthma that are difficult to manage benefit from treating the co-existing food allergies.
Let’s look at non-allergic intolerance to certain foods at first. Some fish when consumed release histamine (the chemical mediator of anaphylaxis) enzymatically (reported with tuna and mackerel) causing nausea, vomiting, itch and flushes, leading to a collapse. Some people have a similar episode if they eat cheese, eggplants and spinach due to the histamine content. Some foods rich in a chemical called serotonin (bananas, avocados, pineapples and tomatoes) cause a similar scenario. So this is an intolerance to the content that cannot be overcome and the immune system is not producing any antibodies. Lactose intolerance in an inherited lack of the enzymes that digest milk and its products, causing abdominal discomfort. Gluten-sensitive enteropathy (more commonly called, celiac disease) is an autoimmune inflammatory disease where the body produces antibodies to the proteins of its own small intestine (and not the foreign antigen like in allergy) upon the ingestion of gluten, a component of wheat protein, in genetically susceptible persons. Sometimes monosodium glutamate (MSG) if added in excess causes flushing, burning and a crawling sensation on skin which resolves within two hours (The Chinese restaurant syndrome).
Although any food can cause allergy, cow’s milk, wheat, soya beans, eggs (this is why we give the yolk that is rich in fat first instead of the white of the egg that has protein) and peanuts are commonly implicated in children. They thankfully outgrow some of these allergies, but nuts and allergy to fish, along with crustacean seafood, are a lifelong problem. Elimination of the allergen for a few years in children whose immune system is still adapting and evolving can help to lose reactivity.