LAUSR

Osteoarthritis (OA) most commonly affects knee joints, and the next most commonly affected sites are the hands and hips. Three distinct hand OA phenotypes have been described: erosive hand OA (EHOA), nodal hand OA — also known as non-erosive hand OA (non-EHOA) — and first carpometacarpal joint OA. EHOA predominantly affects women and is the most aggressive form of hand OA, characterized by a severe clinical onset and progression, leading to joint damage, disability and reduction of quality of life. Clinical signs of inflammation associated with EHOA include the acute onset of pain, swelling and redness. Moreover, EHOA is characterized by radiographic features such as central erosion, saw-tooth and gull-wing lesions and, rarely, ankylosis. The aim of this Review is to report the latest findings on epidemiology, clinical features, pathology and aetiopathogenesis, biomarkers, imaging modalities and treatments for EHOA. The ongoing development of new hand OA classification criteria should facilitate standardization between studies. Erosive hand osteoarthritis is an aggressive condition with poor outcomes. In this Review, the authors describe the clinical features and risk factors associated with erosive hand osteoarthritis, and summarize progress in the areas of biomarkers, imaging, classification criteria and treatment. Erosive hand osteoarthritis (EHOA) is a severe form of hand OA, and evidence suggests that it is characterized by genetic predisposition involving HLA , IL1B and SERPINA1 genes. The radiological hallmark of EHOA is central erosion of the joint, and both radiography and ultrasonography are useful tools for the detection of EHOA. Serological and synovial-fluid biomarkers such as soluble IL-2 receptor and myeloperoxidase are identifiable in EHOA, confirming the role of inflammation in this aggressive form. EHOA biomarkers that are useful in clinical practice have not yet been identified. EHOA is characterized by the presence of signs of inflammation, which correlates with symptoms and the appearance of bone erosions. Currently, no specific treatments are available to slow disease progression in EHOA.