Scientists have successfully treated a patient with disfiguring sarcoidosis, a chronic disease that can affect multiple organs, with a drug approved for rheumatoid arthritis.

Successful treatment of two other patients with similarly severe disease suggests an effective treatment for an incurable, sometimes life-threatening illness is within reach, according to the study published in the New England Journal of Medicine.

Sarcoidosis is an inflammatory disease that affects multiple organs in the body, said researchers from Yale University in the US.

While some sarcoidosis patients recover without treatment, others suffer damage to the lungs, heart, lymph nodes, skin, and other organs.

Based on clues gleaned from prior studies, the team decided to try the arthritis medication tofacitinib.

The drug blocks a pathway known as Jak-STAT.

For several months, a 48-year-old female patient was treated with the drug, a twice-daily pill.

The researchers observed that her skin lesions nearly disappeared. They also performed RNA sequencing on biopsied skin from the patient before and during treatment.

According to Brett King, lead author of the study,

"We plan to evaluate the activation of the Jak-STAT pathway in the lung fluid and blood of over 200 patients with pulmonary and multiorgan sarcoidosis," said Nkiruka Emeagwali, co-author of the study.

These are big steps towards understanding a disease that has been a mystery for years, the researchers said.

The findings are being tested further by the team in a clinical trial. If confirmed, they could represent a breakthrough for sarcoidosis patients, King noted.

"We have a relatively safe medicine that works," King added.