Reports of allergies to sesame seeds appear to be on the rise, particularly in developed nations where sesame is used in everything from hamburger buns to body lotion, according to a new report.

In a review of reports in the medical literature, investigators found that recognized cases of sesame allergy have climbed steadily in the past 50 years, with most reports coming from developed countries. In fact, the study found, research in Australia, Western Europe and Israel suggests sesame is among the more common sources of food allergies.

Reactions to sesame can range from itchy skin and a runny nose to anaphylaxis, a more severe and potentially fatal systemic response that includes symptoms such as breathing difficulty and swelling of the mouth and throat.

The true prevalence of sesame allergy worldwide is unknown, but health authorities in Europe and Canada include sesame on their lists of major food allergens. The authors of the new report argue that the U.S. Food and Drug Administration (FDA) should follow suit and add sesame to its list of eight major food allergens.

Under legislation passed last year, products that contain those eight allergens - milk, eggs, fish, crustacean shellfish, peanuts, tree nuts such as walnuts, wheat and soybeans - must state so on the label.

“We think there should be clear labeling identifying sesame as an allergenic food,” said Dr. Venu Gangur, the study’s lead author.

That could go a long way toward helping people with sesame allergies avoid the food, according to Gangur and his colleagues at Michigan State University in East Lansing.

For their study, published in the Annals of Allergy, Asthma & Immunology, the researchers searched the medical literature for reports on sesame allergy. They found that since the first published case - in the U.S. in 1950 -reports of sesame allergy have increased steadily through the years. In the 1990s, there were more than a dozen research articles describing close to 1,000 patients.

In a study of Australian children, sesame was among the top causes of food allergies, coming in behind egg, milk and peanuts. And a UK government study in the 1990s estimated that 1 in 2,000 in the general population suffers a severe allergic reaction to sesame.

It’s unclear how much of the global increase in sesame allergy is due to an actual jump in cases, and how much is due to greater recognition and reporting of the problem, according to Gangur.

But he and his colleagues suspect that sesame allergy “might be following the same trend” as peanut allergy, which research suggests has doubled among U.S. children in recent years.

Sesame seeds are commonly used in breads, crackers and other baked goods, while sesame oil and sesame paste often turn up in foods such as salad dressings and soups. In addition, Gangur and his colleagues point out, sesame oil is a favorite of the cosmetic and pharmaceutical industries, where it is used in body lotions, lipsticks, ointments and capsules, among other products.

Surprisingly, Gangur noted, there have been no published reports of sesame allergy in India, where the seed is commonly consumed. That could be due to a lack of diagnosis and reporting, he said, but it could also stem from cultural differences in how sesame is prepared and consumed.

Similarly, Gangur pointed out, peanut allergies are only rarely reported in Southeast Asia, where that food is a staple.

SOURCE: Annals of Allergy, Asthma & Immunology, July 2005.