Rheumatoid arthritis patients who use prednisone face a higher risk of developing shingles, but not when using other types of drugs, a new study finds.

Prednisone is a steroid drug often used to treat rheumatoid arthritis (RA), a common chronic inflammatory disorder that typically affects the small joints in the hands and feet.

Researchers at Columbia University looked at 28,852 patients with a mean age of 58 who had suffered from RA for an average of six years.

They found 729 cases of shingles, and also that prednisone users were at a 1.14 percent higher risk of developing the painful nerve disorder. They also found the risk increased as the patients aged.

But the study also found that those patients who used the newer drugs known as disease-modifying antirheumatic drugs (DMARDS) and biologics did not face an additional risk of shingles. DMARDS are drugs used to slow progression of the disease. Biologics are genetically engineered drugs that are employed when other treatments don’t work.

Earlier studies had found that RA was associated with a 1.5 to twofold higher risk for shingles, and they had suggested that older age and the use of prednisone heightened it, but it was undetermined whether the use DMARDs and biologics added it.