Januse kinase (JAK) inhibitors are targeted synthetic disease modifying anti-rheumatic drugs (tsDMARDs) that have risen in popularity as earlier treatment options for rheumatoid arthritis. With multiple JAK inhibitors available in the United States (tofacitinib, baricitinib, and upadacitinib), patients who fail one treatment option have the ability to switch to another agent or change to biologic therapy. 

Still's disease is an autoinflammatory disease characterized by spiking fever, rash, polyarthralgia, sore throat and even life-threatening complications, such as macrophage activation syndrome. It was first described by George Still in the late 1800s.