Every three minutes, a food allergy sends someone in the United States to an emergency department. According to the U.S. Centers for Disease Control and Prevention, food allergies in kids increased about 50 percent between 1997 and 2011.

Every three minutes, a food allergy sends someone in the United States to an emergency department. According to the U.S. Centers for Disease Control and Prevention, food allergies in kids increased about 50 percent between 1997 and 2011. Food allergies now affect about 6 million or 1 in 13 children in the United States, and a third of these kids are allergic to more than one food. Peanut allergies alone have more than tripled from 1997 to 2008. The top eight food allergies among children are peanuts, milk, shellfish, tree nuts, eggs, fish, wheat and soy.

A food allergy is a medical condition in which exposure to a food triggers a harmful immune response. This response, or allergic reaction, occurs because the immune system attacks proteins in the food that are normally harmless. Symptoms may be mild (itchy mouth or a few hives) to severe (throat tightening, difficulty breathing, drop in blood pressure). Anaphylaxis shock is a life-threatening reaction to an allergen that can be sudden and result in death if not treated quickly.

Food allergies are different than food intolerances, which may cause discomfort but are not life-threatening. Food allergies are generally lifelong, especially with peanuts, tree nuts, fish and shellfish; eggs and milk allergies are sometimes outgrown. Food allergies used to be relatively rare. But something changed in the 1990s that started causing kids’ immune systems to overreact to everyday foods. Why the increase in food allergies? No one knows for sure, but following are some theories.

Change in infant feeding recommendations. In 2000, the American Academy of Pediatricians changed infant feeding guidelines to recommend that mothers breast- or bottle-feed exclusively for six months and delay the introduction of common foods associated with allergies. It was recommended to delay dairy until children were 1 year old, eggs until they were 2, and peanuts, nuts and fish until they were 3. This recommendation was not based on solid research but rather on the educated assumption that delaying potential allergens would give an infant’s immune system time to mature.

Hygiene hypothesis. Another theory is that an infant’s immune system must be exposed to an assortment of germs to train itself not to overreact to harmless things. In today’s sanitized world of antibiotics, hand sanitizers, antibacterial soaps and wipes — and with children having less contact with dirt and animals — we may be depriving infants of essential exposure for bolstering the immune system.

Early skin contact. Some believe that infants can be sensitized to foods through their skin, priming them for later allergies. If their first exposure to a food is through an opening in the skin, then they may become sensitive to that protein. This might happen if hands with peanut butter residue come in contact with a rash or cut on an infant. Later, when that food is eaten, the immune system attacks the protein.

Vitamin D deficiency. One study found that the incidence of a peanut or egg allergy was three-times-higher in infants who were vitamin D deficient. It’s estimated that 70 percent of American kids get insufficient amounts of vitamin D, in part because children tend to spend more time indoors than in past generations, reducing their exposure to the sun and thus vitamin D production. Vitamin D is essential for lung and immune system development.

What can be done to decrease food allergies? The National Institutes of Health has revised the infant feeding recommendations to say there is no need to steer clear of common allergenic foods in 4- to 6-month old babies. And in 2017, they revised them again to recommend that kids with elevated allergy risks actually start eating those foods at 4 to 6 months, as long as their allergist or pediatrician approves. This was based on a 2015 trial, Learning Early About Peanut Allergies, by British researchers who found that babies 4 to 11 months old who ate peanut products were 86 percent less likely to develop an allergy.

It might also be beneficial to not be so clean with our kids. Let them play in the dirt, eliminate antibacterial products and stop the overuse of antibiotics. Studies indicate that kids living with pets or who are raised on a farm are less likely to have asthma or allergies.

If you or your child already have a food allergy, it’s important to know what to do in case of an allergic reaction. Avoiding the food is the simple answer, but it’s critical to be prepared at any time for a reaction. If you aren’t sure if it’s an allergy or something else, see an expert to find out.