Canakinumab injection is used to treat certain periodic fever syndromes (inherited conditions in which the body attacks its own tissues and organs causing fever, inflammation, joint and muscle pain, eye redness or pain, stomach pain, rash, and fatigue) including familial cold autoinflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS), tumor necrosis factor receptor-associated periodic syndrome (TRAPS), mevalonate kinase deficiency (MKD)/ hyperimmunoglobulin D syndrome (HIDS), and familial Mediterranean fever (FMF) in adults and children. Canakinumab injection is also used to treat Still's disease (a condition in which the body attacks its own tissues causing inflammation, fever, rash, headache, fatigue, and joint and muscle pain), including adult-onset Still's disease (AOSD) and systemic juvenile idiopathic arthritis (SJIA) in patients 2 years of age or older. Canakinumab is in a class of medications called interleukin antagonists. It works by blocking the activity of interleukin, a substance in the body that causes inflammation.