Pre-teens and teenagers are putting their health at serious risk by using magnetic balls as fake body piercings.
Australian medical authorities are concerned about the magnets, saying they can perforate the intestine if swallowed, resulting in emergency surgery in some cases.
The ball bearing-sized balls are commonly marketed as a desk toy, but tweens and teens place them on either side of their tongue or lip to mimic a piercing.
Fake magnetic ''body piercings'' are also available online.
Paediatric surgeon Prof Andrew Holland from The Childrens Hospital at Westmead says while the magnetic balls might look harmless, parents should be aware of the dangers.
''The magnetic force in these balls is exceptionally strong,'' Prof Holland said in a statement on Wednesday.
''It can quite easily force two pieces of intestine together, leading to twisting or even perforation.''
Once damaged, bowel contents could leak into the abdominal cavity, resulting in a severe infection.
More than 200 cases of children swallowing the balls have been recorded worldwide and Westmead has treated four cases in the past few months.
Among them was eight-year-old Joel Smith, who underwent five hours of emergency surgery after accidentally swallowing six magnetic balls he had been using as fake piercings.
The magnets had clamped on either side of his stomach wall and doctors believed his bowel was just hours away from rupturing.
Dr Holland warned there is also a risk of toddlers ingesting the balls.
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