Skin rashes in people with lupus may have high levels of disease-causing bacteria that can spread to other people, according to a new study.
Researchers found that half of rashes in patients with lupus had abnormally high levels of Staphylococcus aureus (or staph), a common bacteria associated with skin infections.
That means "the person with the rash is a carrier for the bacteria and can spread it to others," said senior author Dr. J. Michelle Kahlenberg, an associate professor of rheumatology at Michigan Medicine, from the University of Michigan.
"In addition, we identified that a protein in the skin of patients with lupus, called interferon, increases the stickiness of staph aureus to their skin," she said in a university news release.
Lupus is an autoimmune disorder, affecting the joints, kidneys, skin, heart and lungs. While skin rashes are a common side effect of lupus, researchers were surprised by the abnormally large staph populations in rashes of people with the disease.
"Patients with lupus had staph colonization on their skin at a rate higher than that reported in healthy adults -- 40% compared to 30%," Kahlenberg said. "And when the patients with lupus had active skin rashes or lesions, that rate increased to 50%."
Staph is a leading cause of infection in patients with lupus, she noted.
"Others have shown it may be associated with disease flares and development of lupus nephritis, or inflammation of the kidney in patients with lupus," Kahlenberg said.
She is now enrolling patients in a clinical trial to test whether topical antibiotics can decrease inflammation and rashes in the skin of lupus patients.
"This is important because if true, the addition of topical antibiotics may be a simple way to improve treatment response in lupus skin and reduce the ability for those rashes to be colonized by staph," Kahlenberg said.
The study was recently published in the Journal of Investigative Dermatology.
The Lupus Foundation of America has more on lupus.