Swallowing desk magnets can tear bowel, doctors say

High-powered magnets in desktop toys pose a growing and lethal threat to children, Canadian doctors are warning.

Ten to 20 times more powerful than older fridge or ferrite magnets, the rare-earth neodymium magnets can attract and anchor to one another across loops of intestine, creating a force so strong it can tear a hole in the bowel, a team from Toronto’s Hospital for Sick Children reports in this week’s edition of the Canadian Medical Association Journal.

According to data from the Public Health Agency of Canada, 328 children under 14 were seen in an emergency department between 1993 and 2007 because of an injury associated with magnets. More than half — 178 — had swallowed magnets.

In the United States, at least 480 cases of high-powered magnet ingestions have been reported over the past decade, according to the North American Society for Pediatric Gastroenterology, Hepatology and Nutrition; 204 of those cases occurred in the past 12 months.

The majority occurred in children six and under. But teens are also inadvertently swallowing or inhaling magnets worn to mimic tongue, lip and nose piercings, the American group warned last October.

In the last year alone, surgeons at the Toronto hospital were asked to see 13 children who had swallowed magnets; four children required surgery and long hospital stays.

Most of the cases involve magnets sold in desktop sets of 50 or 100 balls used to create different shapes. The kits aren’t marketed to children and are labelled to keep out of the hands of children.

“But desks are right at a small toddler’s reach and if they grab one or two, you might not notice they’re missing. If they ingest more than one, that’s when issues come up,” says Dr. Daniel Rosenfield, a pediatric resident at the University of Toronto and Hospital for Sick Children.

Signs of ingestion include vomiting, abdominal pain and fever — symptoms so common in children that they can lead to serious delays in diagnosis, the doctors warn.

The Toronto team describes one case where a child who had “surreptitiously” swallowed a magnet underwent an MRI of his neck for an unrelated health problem. He ended up with a perforated bowel.

Another three-year-old needed laparoscopic surgery to remove three neodymium magnets from his abdomen that had eroded through two loops of intestine. When he was first seen in emergency, his only symptom was drooling. But an X-ray showed three magnets in different parts of his stomach. Because they had not connected with each other and he wasn’t in pain, he was sent home with instructions to his parents to watch his stool for signs the magnets had passed.

Two days later, the child was back in emergency with abdominal pain. “An X-ray showed that all three magnets had come together. We knew at that point that they weren’t going to be going anywhere,” Rosenfield said.

The magnets can attract, causing pressure across the gut, “and that portion of the gut dies as the magnets are pulled together. Once the tissue dies and gets infected, that’s what causes the symptoms.

“It can absolutely require emergency surgery,” including removal of part of the bowel.

There has been one reported death, in a 20-month-old from Seattle, Wash.