Enthesitis-related Arthritis

ABSTRACT

Enthesitis-related arthritis (ERA) is a disease predominantly affecting the joints and entheses of the lower extremities and has the potential to eventually affect the sacroiliac joints and spine evolving to juvenile ankylosing spondylitis. ERA is also characterized by rheumatoid factor seronegativity, paucity of antinuclear antibody, and a strong association with the human leukocyte antigen-B27. ERA accounts for a higher proportion of juvenile idiopathic arthritis (JIA) cases in the Asian population compared to other populations. Advances in the understanding of ERA pathogenesis continue to progress and have led to the development of new treatments targeting pro-inflammatory cytokines. In particular, tumor necrosis factor-α inhibitors have become a mainstay of therapy for patients in whom therapy with anti-inflammatory drugs and/or disease-modifying anti-rheumatic drugs are inadequate or contraindicated. Compared to other JIA subtypes, ERA is associated with a poorer quality of life, worse function, and a higher likelihood of ongoing active disease after the initial treatment. Because the current guidelines for the management of ERA is not considered separately from other categories of JIA, there is a need for treatment guidelines specific to ERA to improve the overall disease outcomes.