"We expected the numbers would be increasing, but we were surprised by how dramatic the rise has been," lead author Dr. Jonathan Silverman of the pediatrics department at the University of Washington in Seattle, said.
To see if that reflected a national trend, the researchers examined Consumer Products Safety Commission data on kids and teens seen for ingestion of magnetic objects at a subset of U.S. hospitals between 2002 and 2011.
The number of annual incidents increased from about one child in every 200,000 in 2002 to six kids per 200,000 in 2010.
Most of the magnets were inserted in the mouth or nose. The number of ER visits for swallowed magnets went up and visits for magnets in the nose went down over the study period, which Silverman said was interesting and unexpected.
A typical child seen for magnet swallowing was five years old; the average kid treated for magnets up the nose was 10.
The data didn't include information about the type of magnets most kids ingested, but small, strong magnets are increasingly found in a range of products, Silverman said.
Other evidence suggests recent increases are largely due to small, spherical balls sold in sets as desktop toys, he said.
"Although not conclusive, this study and several others suggest that the rise in magnet ingestions we found in our study may be due to the rising popularity and availability of these desktop magnet sets," called Buckyballs, he said.
In 2012, the Consumer Products Safety Commission sued Maxfield & Oberton Holdings LLC, the manufacturer of Buckyballs, to stop sale and issue a recall of the products.
Retailers like Amazon, Urban Outfitters and Brookstone agreed to stop selling Buckyballs and similar products, and Maxfield & Oberton stopped manufacturing them, but the toys are still available through some online retailers like Etsy.
Representatives from Etsy did not return a request for comment before press time.
"The greatest danger is from swallowing multiple magnets or a single magnet along with other metal objects," Silverman said.
"Especially when high-powered magnets are ingested, there is a serious risk that they may tear holes in the intestine as they attract together across loops of bowel."
That damage can lead to infection and even death, he said.
Silverman and his colleagues found about 16 percent of children seen in the ER after ingesting multiple magnets were admitted to the hospital, compared to just over 2 percent of those who ingested a single magnet.
More than 90 percent of multiple magnet ingestions happened in 2007 or later, according to results published in the Annals of Emergency Medicine.
"I find the results from this study very alarming," said Dr. Shruti Jayachandra of the department of otolaryngology at Nepean Hospital in Sydney, Australia.
"Young children particularly between the ages of 1-3 years, explore their environment by putting objects into their ears, noses and especially their mouths," Jayachandra, who wasn't involved in the new research, told Reuters Health in an email.
When parents suspect their child has swallowed a magnet they should see a doctor immediately, Silverman said. The doctor will perform an X-ray and either refer the child to a surgeon or choose to observe the child, keeping other magnets and metal, like belt buckles, away, since those can slow the magnet's progression through the digestive system.
Parents should supervise their children and make sure they don't have access to small magnets or button batteries, researchers said.
"On a larger public health scale, increased regulation and enforcement of safety standards may be necessary to drive down the availability of these dangerous toys," Silverman said.
SOURCE: http://bit.ly/15lomUb Annals of Emergency Medicine, online August 8, 2013.