What you don’t know about food allergies

The prevalence of severe food allergies ranges from 10 percent in children 2 years old and 7.1 percent in children 14 to 17 years old to 10.8 percent in adults 18 years and older. While milk, egg, wheat, and soy allergies in infants and toddlers are often passed, others in the Big 9 almost always last a lifetime. And people who weren’t allergic as a child don’t necessarily stay allergic. New food allergies can develop at any age.

According to Dr. Scott H. Sicherer, an allergist at the Icahn School of Medicine at Mount Sinai in New York, and co-authors, “Remarkably, about half of American adults with food allergies report having developed at least one of their food allergies to adulthood. , the shellfish allergy being responsible for the greatest number of these cases.

The only real food allergies are adverse immunological responses, explained Dr Sicherer. The body reacts to an otherwise innocent food as if it were a deadly infection and launches a full-scale offensive. Symptoms can include hives, difficulty breathing, vomiting, or anaphylaxis – a serious and life-threatening shock reaction that occurs seconds or minutes after exposure to an allergen, sometimes in trace amounts. That’s why most airlines no longer offer peanuts to travelers – a simple dusting of peanut dust can prove fatal for some people with peanut allergies.

More than 40 percent of children with food allergies and half of adults with food allergies have at least one serious reaction in their lifetime. Among people allergic to one or more of the Big 9 allergens, rates of severe reactions exceed 27%, with peanut allergy topping the list with 59.2% in children and 67.8% in adults allergic to them. peanuts.

Yet many people who think they have a food allergy do not when tested with a blind oral challenge, in which foods are tested under medical supervision to see if a child responds, the gold standard. to diagnose food allergies. Others mistakenly think of all kinds of adverse reactions to food – from stomach aches to headaches – as allergies. Food intolerance, for example to lactose, the natural sugar in milk, is not an immune reaction but rather results from a deficiency of the enzyme lactase. Many Asians develop a rash and flushing when they consume alcohol because they lack the enzyme to digest it. Other people may think they are allergic because they experience drug-like reactions, such as extreme nervousness from the caffeine in coffee and tea.

Sometimes long-term avoidance of a food can lead to an allergic reaction when that food is ultimately consumed. This can happen to children with skin allergies who avoid milk; they may later experience an allergic reaction when they finally consume it. Occupational exposures, the use of skin care products, and even tick bites can sometimes lead to food allergies in adulthood if there is cross-reactivity with an allergenic substance in both cases.

And whereas previously, families prone to allergies were advised to avoid exposing their children to peanuts until the age of 3 (advice that may have contributed to the current explosion of peanut allergies among children), it now appears that the early introduction – at 6 months – of a highly allergenic food is in fact protective, lowering the risk of a reaction later in life, Dr Sicherer said..