A 25-year-old man previously unable to grow hair on his body, now has a full head of hair thanks to a medication for rheumatoid arthritis called tofacitinib citrate.

The young patient suffered from both plaque psoriasis, a condition involving scaly red areas of skin, and alopecia universalis, an autoimmune disease whereby baldness extends across the entirety of the body.

When the man went to Yale Dermatology to be treated for the psoriasis, Dr. Brett A. King suggested the arthritis drug might address both conditions. The patient took 10 milligrams a day, and the results were rather miraculous.

"The results are exactly what we hoped for," said Dr. King, who recently detailed the treatment success in a study published online in the Journal of Investigative Dermatology. "This is a huge step forward in the treatment of patients with this condition. While it's one case, we anticipated the successful treatment of this man based on our current understanding of the disease and the drug. We believe the same results will be duplicated in other patients, and we plan to try."

Previously, the drug has mainly been used to treat types of psoriasis. But the recent study shows its potential in reversing the effects of alopecia. Doctors believe the drug blocked the patient's immune system from attacking his hair follicles.

"By eight months there was full regrowth of hair," said study coauthor Dr. Brittany G. Craiglow. "The patient has reported feeling no side effects, and we've seen no lab test abnormalities, either."