More button batteries are in use as households increase the number of electronic products they acquire, leading to more injuries, U.S. researchers say. The shiny batteries found in remote controls, watches, musical greeting cards and toys, are about the size of a dime -- the perfect size for a curious child to swallow or even push into the nasal cavity or ear canal, Dr. Kris Jatana, a pediatric head and neck surgeon at Nationwide Children's Hospital in Columbus, Ohio, said. More than 3,400 cases of battery button ingestion annually were reported to U.S. poison centers from 2007 to 2009. It's a challenge for physicians because children might be asymptomatic or present with non-specific symptoms such as irritability, fever, cough, poor oral intake and/or vomiting similar to those of a common viral infection, he said. Smaller batteries, such as those found in hearing aids, will typically pass through the gastrointestinal system on their own, but the larger batteries can get stuck, causing the most significant injury -- eroding through the esophageal wall or airway, causing damage to nearby nerves or eroding into a major blood vessel -- when swallowed by young children, Jatana said. "If a child is suspected of swallowing or pushing a button battery into their nasal cavity or ear canal, the child needs to be taken to an emergency room immediately," he said in a statement. Jatana said a two-view X-ray can establish the presence of such batteries, which can often appear to be "a commonly ingested foreign body in children -- a coin."