Peanuts have the dubious honour of sitting at or near the top of a list of eight high priority food allergens; the others are tree nuts, sesame seeds, milk, eggs, seafood, soy and wheat. Together they account for 90 percent of allergic reactions in American children. Policies restricting consumption of foods containing peanuts began to show up around the mid-1990s, due to concerns about severe reactions such as anaphylaxis. The focus has mainly been on peanuts and to some extent tree nuts, whether we are considering public health and school policies, media coverage, or changes in how products are marketed to the public.
Peanut free schools
School policies range in severity, from those that establish peanut-free or peanut-allowed zones to accommodate the greatest number of students, to those that prohibit all foods that may contain peanuts or tree nuts. These policies are based on the concern that an allergic student could accidentally be exposed to peanut protein (the component that triggers the allergic reaction) through touching a contaminated surface or by smelling a product made with peanut. Since avoidance is the main approach to dealing with food allergies at present, policies intended to protect children in schools, summer camps and other places kids congregate are based on helping affected kids to avoid peanuts.
Does casual exposure represent a risk for students?
Allergies are triggered by peanut protein, not by the components responsible for the smell of peanuts and peanut products. Research published in 2004 by Dr. Tamara Perry of the Arkansas Children’s Hospital Research Institute (ACHRI) shows no peanut proteins in the air after peanuts or peanut butter are eaten. A double-blind placebo-controlled study carried out at at Mount Sinai Hospital in 2003 shows that casual exposure is of little concern. A container of peanut butter was held a foot from the subjects’ noses, and they breathed the air for ten minutes straight. There was not a single reaction to the smell of peanut butter.
The concern over reactions to contaminated surfaces was also addressed by the Mount Sinai study. A pea-sized amount of peanut butter was applied to subjects’ skin and left there for one minute. Only one-third of subjects experienced reactions, all of which were mild localized skin rashes. None required medication of any kind.
The authors of the Mount Sinai study caution that the same pea-sized amount of peanut butter could cause severe reactions if accidentally ingested (for example, if an individual touched a contaminated surface and then their mouth.) However, Dr. Perry notes that washing with regular soap and water leaves no trace of peanut allergen on the hands. Tables and other surfaces washed with cleaning wipes and other cleaning agents, except dish soap, also showed no residual allergens.
Cure for peanut allergy?
There was much excitement earlier this year, when British researchers led by Dr. Andrew Clark began a large trial of their oral desensitization protocol for peanut allergies. It is expected that results will be published within three years, and that if all goes well the protocol will be made available to the public. While this is encouraging news, schools and students with peanut allergies still have to cope from day to day. Doctors discourage changing avoidance protocols because of the hope that peanut allergies will one day be treatable. However, parents and schools may want to examine existing peanut-free policies in light of research that defines the actual risks, especially if there is difficulty enforcing policies.
Sources:
“Be food allergy aware when packing school lunches.” Health Canada
“Peanut allergy treatment could be on the horizon.” CTV News
Tamara T Perry, M.D. et al, “Distribution of peanut allergen in the environment.” The Journal of Allergy and Clinical Immunology
Steven J. Simonte, M.D. et al, “Relevance of casual contact with peanut butter in children with peanut allergy.” The Journal of Allergy and Clinical Immunology“
