March 16, 2009 (Washington, D.C.) -- Blame the hummus!
Sesame seed allergies are rapidly rising in the U.S., but most Americans never even consider sesame bagels, hummus, or other sesame-containing foods as the source of their or their kids’ allergies, food allergy experts say.
And if your child is allergic to tree nuts, there’s a good chance he or she is allergic to sesame as well, new research shows.
“Sesame allergies have probably increased more than any other type of food allergy over the past 10 to 20 years,” says Robert Wood, MD, director of the division of pediatric allergy and immunology at Johns Hopkins University School of Medicine in Baltimore.
“They’re now clearly one of the six or seven most common food allergens in the U.S.,” he tells WebMD.
Yet, the FDA does not recognize them as such, as there are no well designed studies looking at how many cases occur each year, Wood says. The FDA blames milk, eggs, fish and shellfish, tree nuts, peanuts, wheat, and soybeans for 90% of food allergies in the U.S.
That’s why Ama Alexis, MD, isn’t surprised that there is little awareness of this type of allergy. Alexis, a fellow in the division of allergy and immunology at Schneider Children’s Hospital in New Hyde Park, N.Y., is one of several researchers trying to better characterize sesame allergies in the U.S.
Alexis traces the steady rise in cases to a more ethnically diverse diet.
“We’re eating more foods that contain sesame seeds: falafel, tahini, hummus, and halvah, for example,” she says.
On top of that, “three quarters of Mexico’s sesame seeds go to McDonald’s for their sesame buns. Sesame is also widely used in cosmetics like lipsticks and moisturizing creams,” Alexis tells WebMD.
To find out more about sesame allergy, Alexis and colleagues mined the medical records of patients with a food allergy seen at their clinic between 2005 and 2008. They identified 17 patients with sesame allergy, ranging in age from 8 months to 44 years.
The findings were presented at the annual meeting of the American Academy of Asthma and Immunology.
Their most common symptom was hives, in 41% of patients, followed by eczema in 29%. Twenty-three percent developed a dangerous swelling of the face and of the throat that blocks airways, referred to as angioedema. Stomach upset and wheezing or other breathing problems were also common, affecting 23% and 12% of patients, respectively.
All but one patient had a strong family history of allergies. And 70% of the patients were also allergic to tree nuts, while 65% were allergic to peanuts.
In a separate study, Boston researchers found that kids who have had allergic reactions to tree nuts are nearly three times more likely to have allergic reactions to sesame seeds. The relationship between peanut and sesame allergies was less clear, says researcher Lisa Stutius, MD, of Children’s Hospital Boston.
The findings suggest that tree nut-allergic children with unexplained hives, eczema, or other allergy symptoms might want to visit their allergist to determine if they’re allergic to sesame as well, the doctors say.
But a third study showed that standard skin and blood testing for food allergies “doesn’t predict whether a child has true sesame allergy,” says Permaul Perdita, MD, also of Children’s Hospital Boston.
“The only way to really tell is to give them sesame seeds and see if they have a reaction,” she says.
Such testing needs to be performed under medical supervision because there is a chance that the patient could have a potentially life-threatening anaphylactic reaction, Perdita tells WebMD. “What we really need is a better blood or skin test.”