Even when children aren’t physically harmed, the incidents can take a psychological toll, causing distress and anxiety and affecting their quality of life. Children may refuse to go to school, or become socially isolated, depressed or even suicidal, experts say.

The bullying problem is widespread. Some 5.9 million children in the United States, or about one in 13, suffer from food allergies, and studies have found that close to one in three children with food allergies have been bullied specifically because of their allergy.

Most of the bullying is done by other children who are peers or classmates, but adults may also make insensitive remarks. All too often, children make the mistake of not telling their parents they are being bullied, even though studies have found that adult involvement is effective and can usually put a stop to the behavior. As children get older, however, they are more reluctant to have their parents get involved.

Among children who were bullied, one study found, more than half said they had been touched by an allergen, had an allergen thrown or waved at them or had their food intentionally contaminated with an allergen.

“Most of the bullying was verbal, as in ‘Ha ha, you can’t eat this,’ but occasionally they would wave the food at the person and threaten them with it, and if they dropped the allergen into the child’s own food, that could cause a serious reaction,” said the author of that study, Dr. Scott H. Sicherer, director of the Jaffe Food Allergy Institute and chief of pediatric allergy and immunology at the Icahn School of Medicine at Mount Sinai in New York City.

Last fall, the company Kaléo Pharma and several advocacy organizations — including the Allergy & Asthma Network, Food Allergy & Anaphylaxis Connection Team, Food Allergy Research & Education and Kids with Food Allergies — started a campaign against bullying in an effort to stamp it out.

The campaign’s goal is to convey to would-be bullies that attacking someone with allergens is not merely cruel; it could be deadly.