Food allergies have been on the rise in the U.S. since at least the '90s, data show. According to the U.S. Centers for Disease Control and Prevention, almost 6% of adults and children have a food allergy, and it’s a growing food safety and public health concern.
Today, it's common to see menus with labels indicating which dishes contain nuts, milk, eggs, or other common food allergens. Many grocery stores have a wide selection of allergen-free food options.
While there is increased awareness about food allergies, there are also a number of harmful myths plaguing the allergy community. Here are some of the top misconceptions about food allergies, according to experts.
Food intolerances or sensitivities are the same as food allergies
"A food allergy is a reaction of our immune system, which produces antibodies that identify foods as harmful, and that results in other chemicals being released which causes an allergic reaction," Dr. Adela Taylor, allergist and immunologist at Mayo Clinic, tells TODAY.com. Food sensitivities or intolerances don't involve the immune system and are non-life threatening, Taylor adds.
Allergic reaction symptoms often include hives, swelling of the face or lips, wheezing, throat tightness or vomiting, Dr. Scott Sicherer, pediatric allergist, immunologist and professor at the Icahn School of Medicine at Mount Sinai, tells TODAY.com. A life-threatening allergic reaction (anaphylaxis) can cause a drop in blood pressure or loss of consciousness, he adds. "All that typically happens pretty quick," says Sicherer — it can only take minutes.
"An intolerance typically has to do with a metabolic process," says Sicherer. Often a person lacks a chemical or enzyme needed to digest a certain food, per Mayo Clinic. Lactose intolerance, for example, occurs when someone has problems digesting the sugar in milk (lactose), which can lead to gas, bloating, upset stomach or diarrhea. Food intolerance symptoms can begin hours or even days after ingesting a food.
Food allergy tests are always accurate
"One misconception is that an allergy test by itself tells people whether they have an allergy or not," says Sicherer, adding that diagnosing a food allergy involves a full evaluation by an allergist.
There are two classic food allergy tests. During a skin test, a drop of an extract of the food is put on the skin and scratched. Then a doctor will look for signs of a reaction, usually a red bump. A blood test measures the amount of a protein that the immune system makes in response to an allergen, called an IgE antibody.
But these tests can yield false positives because "it's not a yes or no test, it's much more of a statistical test," says Sicherer. "The bigger that bump on your arm or the higher the blood test results, the more likely it is that you're allergic." A key part of diagnosing a food allergy is looking at a patient's history and past reactions, he adds.
Doctors may also diagnose a food allergy using an "oral food challenge," where they give patients small amounts of a food under medical supervision and measure their reaction, says Taylor.
The experts caution against at-home allergy tests or self-diagnosing. "If you think you're allergic to something, you should see an allergist," says Sicherer.
Airborne exposure can cause a severe allergic reaction
Another myth? "That just smelling a food is very dangerous or there's a real risk from airborne exposure," Dr. Robert Wood, director of pediatric allergy and immunology at Johns Hopkins Children's Center, tells TODAY.com.
“It's a myth that does affect people’s lives," Wood says. "I see patients who will never even get on an airplane because of the fear that there might be peanuts on board."
According to Taylor, studies have shown that the amount of peanut allergen particles trapped in the airplane filter is far too small to cause an allergic reaction.
It is possible for food allergens to become airborne, says Wood — for example, if someone is in the immediate vicinity of the food being cooked, especially at a high temperature. "If a child with a severe egg allergy is in a mom's arms while she's frying an egg, that child may have a reaction," says Wood, but these airborne reactions are rare and typically not severe.
“Where airborne reactions are feared the most, airplanes and school cafeterias, it's a lot of concern without any real justification,” says Wood.
Some people do develop a reaction when a food they're allergic to touches their skin, but it's typically only a rash or hives. "It’s not going to cause a life-threatening allergic reaction. You have to swallow it," says Taylor.
Every reaction will be worse than the one before
"Food allergy reactions are very unpredictable, and there are a lot of variables that go into how severe a food reaction may be," says Taylor. Symptoms can even vary each time.
There's no general rule or pattern of severity that allergic reactions follow, says Sicherer, adding, "You shouldn’t assume things, because if you’re wrong, it could be consequential."
People with food allergies should always be prepared for a severe reaction, says Taylor, which may involve carrying antihistamines or epinephrine, the first-line treatment for anaphylaxis.
Peanuts are the most dangerous allergy
"There isn't one single food that is more dangerous in terms of food allergies," says Taylor. Although peanuts are one of the top foods that account for most food allergies, Taylor says, any food can cause an allergic reaction, and any reaction can be severe.
"It's very common for people, whether it be a teacher or a restaurant worker, to think a peanut allergy should be taken seriously, but a milk allergy doesn't have a serious risk," says Wood.
One possible reason, he adds, is there is more misdiagnosis of milk allergies in people who have lactose intolerance, which does not have a dangerous outcome.
"Peanut allergy has also gotten a lot more publicity," Wood says, adding that there are more kids who get severe reactions to foods that aren't peanuts than kids with severe peanut allergies.
You only develop food allergies during childhood
"The majority of food allergies do occur in babies and children, but you can develop food allergy at any point in time in life," says Taylor. Adults may suddenly become allergic to a food they've been able to eat for their entire lives, the experts note.
That said, certain allergies are more prevalent in children compared to teens and adults. "Milk and egg allergy are clearly more common in the first five years of life .... then peanut allergy is the most common in school-age children and adolescents, and shellfish allergy is by far the most common allergy in adults," says Wood.
It is rare to develop a new peanut allergy in adulthood but possible, says Wood. "No one should assume that an adult who believes they have a new food allergy couldn't have one," says Wood.
Additionally, food allergies diagnosed during childhood don't always last forever. "Most children most outgrow allergies to milk, egg wheat, soy. ... 20% of young children outgrow an allergy to peanuts and 10% of young children outgrow a tree-nut allergy," says Sicherer.
Babies should not be given major food allergens
"The previous thought was to completely avoid foods that can cause severe allergies (milk, eggs, nuts), and I think that may be one of the biggest reasons that we have food allergies like we do today," Dr. Sandra Hong, chair of the allergy and immunology department at the Cleveland Clinic, tells TODAY.com.
The old recommendation was that for babies with a higher risk of developing food allergies (those who have eczema or a parent with a food allergy) to wait to introduce milk until age 1, eggs until age 2, or nuts until age 3, says Hong — but this is outdated.
“The recommendations nowadays are not to delay introduction of these common allergens, and to give them in child-safe forms as you would any other food," says Sicherer.
There is growing evidence from clinical trials that early introduction of foods like peanuts, for example, could potentially reduce peanut allergy among high-risk infants, says Hong. "We've been treating babies that show evidence of allergies and having amazing results. They are able to eat and tolerate the foods," says Hong.
The research around treating food allergies is promising, Hong adds. "It could change lives."