A recent study found that nearly half of adults have adult-onset food allergies and the most common allergy in adults is shellfish. Photo by stokpic/PixaBay

Oct. 27 (UPI) -- Food allergies are common among children, however, a recent study found that almost half of all adults with food allergies had adult-onset food allergies.

The study, published in the November edition of the Annals of Allergy, Asthma & Immunology, and presented this week at the American College of Allergy, Asthma and Immunology Annual Scientific Meeting, revealed a significant increase in the prevalence of food allergies in adults.


"Food allergies are often seen as a condition that begins in childhood, so the idea that 45 percent of adults with food allergies develop them in adulthood is surprising," Dr. Ruchi Gupta, ACAAI member, said in a news release. "We also saw that, as with children, the incidence of food allergies in adults is rising across all ethnic groups."

Researchers found the rate of adults diagnosed with shellfish allergies has risen from 2.5 percent in 2004 to 3.6 percent. It's the most common allergy among U.S. adults. Adult tree nut allergies have increased to 1.8 percent compared to 0.5 percent in 2008.

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It is believed that many adults do not often realize they have a food allergy and instead believe they have food intolerance, thereby not seeking treatment from an allergist.

A 2014 study by Northwestern University found that of 1,111 adult food allergy patients, 15 percent were first diagnosed over age 18 and most had their first reaction in their mid-30s. The study also showed that unlike food allergies in children, more adult women than men were diagnosed with adult onset food allergies.

"Our research also found that, among black, Asian and Hispanic adults, the risk of developing a food allergy to certain foods is higher than for whites, specifically for shellfish and peanuts," Christopher Warren, Ph.D. candidate, said.

"For example, Asian adults were 2.1 times more likely to report a shellfish allergy than white adults, and Hispanic adults reported a peanut allergy at 2.3 times the frequency of white adults. Because many adults believe food allergies mostly affect children, they may not think to get tested. It is important to see an allergist for testing and diagnosis if you are having a reaction to a food and suspect a food allergy."