NEWARK, N.J., July 20 (UPI) -- Children who are prescribed antibiotics have twice the risk of developing juvenile arthritis as children who don't take the drugs, and the risk increases with each round of antibiotic treatment they are exposed to, according to researchers.
Previous studies have found that about a quarter of antibiotic treatments prescribed to children, and half the ones for acute respiratory infections, are unnecessary for infections that often can get better on their own.
About 1 in 1,000 children experience juvenile arthritis, with about a quarter of those having genetic causes.
"Our research suggests another possible reason to avoid antibiotic overuse for infections that would otherwise get better on their own," Daniel Horton, a postdoctoral research fellow in the Department of Pediatrics at Rutgers Robert Wood Johnson Medical School, said in a press release.
Researchers in a study published in Pediatrics analyzed medical data for 450,000 children collected by The Health Improvement Network, comparing 152 children newly diagnosed with juvenile arthritis with age- and gender-matched children who do not have the condition.
The data showed any treatment with antibiotics doubled the chances of juvenile arthritis, and that repeated antibiotic treatments increased the risk factor significantly with each course of treatment. The highest chances for arthritis to develop was within one year of antibiotics being taken.
Children who were treated with antibiotics for an upper respiratory tract infections were more likely to develop arthritis than those who didn't receive antibiotics, researchers found.
Horton said that viral infections have been suggested as a cause for juvenile arthritis, however several studies have contradicted the idea. But children with arthritis have have a higher risk for serious disease because their immune systems are weaker.
"So an alternative explanation to our findings is that this abnormal immune system makes children more susceptible to serious infection even before they are diagnosed with arthritis," Horton said. "Under this hypothesis, antibiotics would be a marker for abnormal immunity rather than a direct cause of arthritis. A majority of children get antibiotics, but only about 1 in 1,000 get arthritis. So even if antibiotics do contribute to the development of arthritis, it's clearly not the only factor."