CHICAGO, Jan. 8 (Xinhua) -- More than 10 percent of adults in the United States, or over 26 million, are estimated to have food allergy, and nearly twice as many people believe they have food allergy but report symptoms that are inconsistent with a true food allergy, a study showed.
Based on a nationally representative survey of more than 40,000 adults, the study found that only half of adults with food allergy symptoms had a physician-confirmed diagnosis, and less than 25 percent reported a current epinephrine prescription.
Moreover, nearly half of food-allergic adults developed at least one of their food allergies as an adult.
"We were surprised to find that adult-onset food allergies were so common," said lead author Ruchi Gupta, a professor of pediatrics at Northwestern University Feinberg School of Medicine and a physician at Lurie Children's Hospital. "More research is needed to understand why this is occurring and how we might prevent it."
The study data indicate that the most prevalent food allergens among U.S. adults are shellfish, affecting 7.2 million adults; milk, affecting 4.7 million; peanut, affecting 4.5 million; tree nut, affecting 3 million; fin fish, affecting 2.2 million; egg, affecting 2 million; wheat, affecting 2 million; soy, affecting 1.5 million; and sesame, affecting 0.5 million.
"Our data show that shellfish is the top food allergen in adults, that shellfish allergy commonly begins in adulthood, and that this allergy is remarkably common across the lifespan," Gupta said. "We need more studies to clarify why shellfish allergy appears to be so common and persistent among U.S. adults."
Food allergy can trigger a life-threatening reaction. "It is important to see a physician for appropriate testing and diagnosis before completely eliminating foods from the diet," Gupta said. "If food allergy is confirmed, understanding the management is also critical, including recognizing symptoms of anaphylaxis and how and when to use epinephrine."
The study was published Jan. 4 in JAMA Network Open.