One year in review 2018: axial spondyloarthritis.

Spondyloarthritis (SpA) is the umbrella term for a broad spectrum of inflammatory rheumatic diseases with typical but also rather different clinical manifestations, limited laboratory abnormalities and characteristic imaging features. For classification purposes, a so-called non-radiographic form (nr-axSpA) is differentiated from a radiographic one (r-axSpA) which is almost identical to the classical ankylosing spondylitis (AS) that is genetically strongly associated with the major histocompatibility complex class 1 antigen HLA-B27. In axSpA, the axial skeleton is affected by both inflammation and new bone formation, and joints might be affected. Rather typical musculoskeletal manifestations of SpA are enthesitis and dactylitis, the latter mainly in psoriatic arthritis (PsA). Extra-articular manifestations such as acute anterior uveitis (AAU), psoriasis (PsO) and inflammatory bowel disease (IBD) are also typical of SpA. In this paper we review the literature on axial SpA (ax-SpA) of 2018 (Medline search of articles published from 1st January 2018 to 31st January 2019).