New Research In Food Allergies Presented At Annual Meeting

Despite the requirement for prior contact with an allergen for sensitization to occur, the majority of peanut allergic children react to their first known peanut ingestion. Evidence suggests that sensitization may occur by contact with allergen through the skin. Individuals thus sensitized may be predisposed to developing peanut allergy, while tolerance to peanut may be induced by oral exposure.

S.M.H.Chan, MD and colleagues at King's College in London presented their study at the American Academy of Allergy, Asthma & Immunology (AAAAI) Annual Meeting in Philadelphia. The researchers employed the use of skin and gastrointestinal homing memory T cell markers to indicate the likely route of initial sensitization and examine the evidence for this theory. Immunomagnetic beads were used to isolate CLA+ and ?4?7+ memory T cells from peripheral blood mononuclear cells.

In vitro evidence supports the hypothesis that sensitization to peanut via the skin may be associated with the development of peanut allergy, while oral sensitization may induce tolerance. Such further studies may help to facilitate the diagnosis of peanut allergy.

Consumer attitudes and response to new food allergen labeling

Food allergic consumers (FAC) depend upon clear, accurate ingredient labels. Sam S. Ahn, MD and colleagues with Mt. Sinai School of Medicine in New York, NY examined FAC's opinions and responses subsequent to the Food Allergen Labeling and Consumer Protection Act (FALCPA).

Parents of children with food allergies completed a survey. The results of the survey indicated that FAC read labels "always" on purchase (90%) and upon preparing to use (85%) packaged foods. Participants with an opinion rated toll-free numbers (61% "very helpful") and package information (67% "very helpful") as more helpful for allergen information than corporate websites (40%), response to letters/email to the company (43%) and company sponsored brochures (30%).

FACs "agree-strongly agree" that since FALCPA it is easier to find allergens on labels (95%) and are more confident about label accuracy (74%). Only 28% of participants correctly knew that FALCPA exempts raw meat products. Increased use of advisory statements ("may contain") was noted by 63%.

The new labeling laws have resulted in strong consumer satisfaction and a modest increase in confidence, but FACs are noting an increase in advisory labels, increasingly ignoring them, and may not understand the full details of the law.

Oral Peanut Immunotherapy for Children with Peanut Allergy

The goal of the study by Scott D. Nash, MD and colleagues at Duke University, Durham, NC was to determine if peanut oral immunotherapy (OIT) can desensitize peanut allergic children to peanut protein.

The study included children with a clinical history of peanut allergy and peanut specific IgE?15kU/L. The study was divided into 3 phases; a modified rush initial day of multiple doses, a build up phase of daily doses, increasing the dose every 2 weeks, and a daily maintenance phase for 4 months followed by an open food challenge (OFC) using peanut flour. Peanut specific IgE, IgG, and IgG4 were measured at specific intervals.

Thirteen children completed the study and have undergone OFC. All subjects tolerated the full OFC (7.8 gms peanut flour) Eight subjects had no symptoms. Five subjects experienced mild symptoms with four being treated with diphenhydramine. During the modified rush phase most subjects had mild allergic symptoms but two subjects experienced significant, systemic allergic symptoms.

Peanut OIT is effective for decreasing the risk of a significant allergic reaction after accidental peanut ingestion. Immunologic changes correlate with other forms of allergen-specific immunotherapy.

Analysis of 1016 commercial food ingredient labels to review Food Allergen Labeling and Consumer Protection Act (FALCPA) compliance, use of advisory statements, and possible pitfalls for food-allergic consumers

Labeling terminology has changed since FALCPA; however labeling practices impact food-allergic consumers but have not been extensively assessed. Danna Chung, MD and colleagues at Mt. Sinai School of Medicine in New York along with trained surveyors assessed 1016 commercial products.

At least one "major" allergen was listed for 73% of products. Allergen disclosure techniques included: separate warnings, using bold font, and parentheses. Regarding advisory labeling (not regulated by FALCPA), 19 different types of terminology were found; the most common terms were "Manufactured in a facility that also processes" and "May Contain" (each 27%).

When advisory labels listed tree nuts, the type(s) were typically undisclosed. "Allergen-free" terminology was found in less than 1% of products. Additional discrepancies and ambiguities included: non-disclosure of sources of gelatin and lecithin, and the simultaneous disclosure of "contains" and "may contain" for the same allergen.

The study concluded that general compliance with the FALCPA legislation appears high, though discrepancies and ambiguities resulting in non-compliant disclosure were identified. There are many circumstances where lack of full ingredient disclosure would present obstacles for persons with allergies to foods not considered "major allergens." Finally, consumers are exposed to an array of advisory labeling terms, not regulated by the FALCPA, presenting varying details and unclear risk disclosure.

Allergic status of schoolchildren with food allergy to egg, milk or wheat in infancy

Although children allergic to egg, milk or wheat in infancy tend to become tolerant by school age, allergic status after remission has not been well evaluated. T. Kusunoki MD, PhD and colleagues at Shiga Medical Center for Children, Moriyama, Shiga, JAPAN and the Department of Pediatrics, Graduate School of Medicine, Kyoto University, Kyoto, JAPAN investigated allergic status of schoolchildren who avoided egg, milk or wheat due to immediate-type food allergy diagnosed at less than 1-year-old (early food avoiders), through analysis of a large-scale questionnaire-based survey of schoolchildren.

A questionnaire on allergic diseases was distributed to the parents of 14,669 schoolchildren aged 7-15 years in 30 schools in Kyoto, Japan. Of these, 13,215 questionnaires were recovered (return rate, 90.1%).

Although more than 80% became tolerant to these foods by school age, avoidance of other foods (buckwheat, shellfish, fruits and others) was seen at much higher frequencies than in non-early food avoiders at school age. Moreover, prevalence of asthma, atopic dermatitis and allergic rhinitis was higher in this group. These risks further increased in the subgroup of children who had not gained tolerance to egg, milk or wheat by 3 years old.

The rate of early food avoiders increased as age decreased, indicating a rising trend of food allergy in infancy. At school age, early food avoiders appear to have a higher risk of not only other allergic diseases but also allergy to other food allergens, indicating the need for continuous attention to food allergy.

The AAAAI represents allergists, asthma specialists, clinical immunologists, allied health professionals and others with a special interest in the research and treatment of allergic disease. Allergy/immunology specialists are pediatric or internal medicine physicians who have elected an additional two years of training to become specialized in the treatment of asthma, allergy and immunologic disease. Established in 1943, the AAAAI has more than 6,500 members in the United States, Canada and 60 other countries.

American Academy of Allergy, Asthma & Immunology