The death of a Quebec mayor who was stung multiple times after stepping on a wasps' nest while gardening is a tragic but cautionary tale for those who run afoul of bees, hornets or other stinging insects — especially if they have a severe allergy to their venom, experts say.

Photo: Contributed

Lucie F. Roussel, the mayor of La Prairie, died from wasp stings.

Lucie F. Roussel, mayor of La Prairie, died in hospital Sunday after being stung at least 15 times in the garden of her cottage near Stratford, Que., municipal authorities said.

There are conflicting reports as to whether the 51-year-old widowed mother of two teens had an allergic reaction, but La Prairie spokeswoman Chantal Charron said Roussel had never been diagnosed with an allergy to wasp stings.

"She was not diagnosed by a doctor. She did not know that she was allergic — if that was the case," Charron told The Canadian Press, noting that Roussel had emergency injectable epinephrine at her home because her late husband had been allergic.

Dr. Susan Waserman, an allergist at McMaster University, said it's extremely uncommon for someone to die as a result of insect venom directly, although there are a few cases in the medical literature.

"It's possible, but it's rare," Waserman said Tuesday from Hamilton. "This is not a common phenomenon."

Most deaths that result from insect stings are caused by a severe, life-threatening allergic reaction known as anaphylaxis, which can be marked by such symptoms as breaking out in diffuse hives, having difficulty breathing, feeling lightheaded and sometimes vomiting, she said.

"Usually, most acute allergic reactions occur within minutes to an hour," Waserman said, noting that people may feel their tongue start tingling and their throat swelling.

"And if you have no reason to believe you are allergic, many people are caught off guard, and they don't generally carry an epinephrine auto-injector."

Epinephrine is a form of adrenalin, given by a shot typically in the muscles of the thigh, that can counteract the allergic reaction until the affected person can receive medical treatment in hospital or by paramedics.

Symptoms of anaphylaxis can vary from one person to another and even from one reaction to the next, said Beatrice Povolo, a spokeswoman for the charitable advocacy group Anaphylaxis Canada.

What makes this allergic reaction so life-threatening is that the airways often swell and the blood pressure plummets, sending the person into anaphylactic shock.