Cases of Nut Anaphylaxis Spike in Children at Halloween and Easter

By Linda Carroll

September 25, 2020

(Reuters Health) - The number of children showing up in emergency departments with anaphylaxis may spike during Halloween and Easter, a new study suggests.

Canadian researchers found that peanut-triggered anaphylaxis cases jumped by 85% over the daily average during Halloween and by 60% during Easter, according to the report published in the Canadian Medical Association Journal.

In cases where the type of nut was unknown, there was an increase of 70% during Halloween and Easter compared to the rest of the year.

"Caregivers in the family and hospital should be aware of the high risk of peanut/tree nut anaphylaxis at certain times of the year," said the study's lead author, Melanie Leung, a fourth-year medical student at McGill University. "Educational tools are needed to raise public awareness of this phenomenon."

Policy changes might also help reduce the number of children experiencing anaphylaxis during these holidays, Leung said in an email.

For example, Leung said, those might include "labeling of one-bite snacks and public campaigns such as 'Teal Pumpkin,' signaling households where peanut- and tree-nut-free snack distribution is available."

For the study, Leung and her colleagues established a large registry that recruited patients with anaphylaxis presenting to pediatric emergency departments in four Canadian provinces: Quebec, Ontario, Newfoundland and Labrador.

In their analysis, the researchers focused on data from April 15, 2011 to January 31, 2020 from patients younger than 18 who had presented with unknown-nut-, peanut- or tree-nut-induced anaphylaxis. Calendar days were units of observation and were classified into four multiday periods for the primary analysis: Halloween, Christmas, Easter and the rest of the year, excluding other holidays. In a secondary analysis, the researchers extended their scope to include seven categories: Halloween, Christmas, Easter, Diwali, Chinese New Year, Eid al-Adha and the rest of the year.

Those particular holidays were chosen because they were most celebrated by children and the children were more likely to be exposed to peanuts and tree nuts during those times.

From 2011 to 2020, there were 1,390 cases of nut-induced anaphylaxis, with 864 (62.2%) in boys. The median age of the children was 5.4 years.

While anaphylaxis triggered by unknown nuts and peanuts spiked during Halloween and Easter, there was no variation in daily count on any of the other holidays. The researchers also saw no increase in anaphylaxis cases due to tree nuts during holidays.

The researchers suspect that the reason for the increases they did see during the two holidays is that those are times when children receive candies and other sweets from people who may not be aware of their allergies. The explanation for the lack of an increase at Christmas may be the fact that it is a holiday in which celebrations are more intimate, involving mostly family and friends, the authors note.

Dr. Corinne Keet wasn't surprised by the study's findings. Halloween is a time when kids are eating things not provided by their parents, said Dr. Keet, an associate professor of pediatrics at the Johns Hopkins School of Medicine in Baltimore. "We see this within our own patients," she added. "Reactions are more frequent around Halloween."

One possible silver lining to the current pandemic, Dr. Keet said, "is that this may be the year that children with food allergies have an advantage - they are used to Halloween being different."

The lack of an uptick at Christmas surprised Dr. Amanda Cox, a pediatric allergist and an assistant professor at the Icahn School of Medicine at Mount Sinai in New York City. "When you think of Christmas, people are always making lots of cookies and depending on the culture they may have nuts in them," she added.

What the researchers found may be the tip of the iceberg, Dr. Cox said. "Mild reactions are also happening. They were tracking only cases of anaphylaxis."

While it's likely that the Canadian results would apply to the U.S., it would be good to see it confirmed, said Dr. Laura West, an assistant professor of pediatrics in the department of allergy and immunology at the University of Pittsburgh and the UPMC Children's Hospital of Pittsburgh.

"I always warn families during the holidays when there are multiple potluck-style dinners that baked goods could be contaminated with tree-nuts or peanuts," Dr. West said. "I've had patients where someone made peanut cookies followed by sugar cookies and there was enough peanut residue in the pan for a reaction in a susceptible child."

SOURCE: CMAJ, online September 23, 2020.