Small children sometimes swallow things they shouldn’t.

Of course, many household items pass through kids’ digestive systems without causing any harm, just worry.

But that’s not always the case.

Two articles in the journal Pediatrics describe a serious threat that’s ubiquitous but overlooked.

And every parent should be aware of it.

The threat is something called a button battery.

These are small electric batteries shaped like coins.

They’re used in many electronic devices, everything from hearing aids and remote-control units to toys and greeting cards.

In recent years, button batteries made with lithium have become much more common. One of the most popular models is slightly larger than a penny.

That’s the one doctors are worried about.

This battery is large enough that if a child under age four tries to swallow it, the battery can become lodged in the esophagus.

If that happens, the battery can cause severe chemical burns, due to a reaction that happens when the battery gets wet.

The injuries can occur in as little two hours, if the battery isn’t removed.

In one of the journal articles, researchers analyzed about eight-thousand button battery ingestions from 1990 to 2008.

More than eighty children suffered serious injury or death.

Among these worst-case-scenario situations, ninety percent involved large-diameter lithium batteries.

The researchers suggested that manufacturers modify all devices using button batteries, making the batteries harder to access.

That seems like a good idea, but forty percent of the ingestion cases involved batteries that were lying around the house, or sealed in their original packaging.

So it’s not realistic to expect industry to solve the problem alone.

Parents have to help, too, by using vigilance, foresight and pre-emptive action.

And until small children stop being curious and reckless, it’s the best remedy moms and dads have.