Oligoarticular disease

Oligoarthritis is a pattern of arthritis which most commonly resolves into a member of the spondyloarthritis family or sarcoidosis. Uncommonly it progresses to forms of arthritis more commonly associated with polyarthritis or monoarthritis and rarely it is associated with malignant or paraneoplastic syndromes. Three key aspects of diagnosis are consideration of possible diagnoses in the patient's age and ethnic groups; careful consideration of the personal and family history; and a search for and correct identification of characteristic associated features. This frequently involves collaborative working with other specialists including dermatologists, ophthalmologists, genitourinary physicians, respiratory physicians, and others. Precise diagnosis usually then involves subsequent investigation for diagnostic features including evidence of recent infection, HLA B27, autoantibodies, tissue-specific features of sarcoidosis, inflammatory bowel disease, and, occasionally, malignant disease. Management is dependent on clear diagnosis and precise delineation of underlying conditions such as infection. The purpose of this chapter is to provide a guide to the diagnostic approach and an algorithm for routine clinical practice. Detailed descriptions of the conditions included and investigations appropriate for the establishment or exclusion of individual diagnoses are discussed elsewhere in this volume.