Monoarthritis: inflammation of a joint (arthritis) that occurs in one joint at a time. Infection, trauma, and crystal-induced arthritis (for example, gout, pseudogout) are the most common causes of monoarthritis. QUESTION The term arthritis refers to stiffness in the joints. See Answer From Arthritis Resources Tips to Pamper Your JointsKeeping Up With Your RA Through TelemedicineTreatments for Your Rheumatoid Arthritis Featured Centers Good and Bad Foods for PsoriasisVideo: Getting Personal on Life With MS Health Solutions From Our Sponsors Shot-Free MS Treatment Your Child and COVID-19 References Longo, D.L., et al. Harrison's Principles of Internal Medicine, 18th ed. United States: McGraw-Hill Professional, 2012.