Musculoskeletal

An HLA-B27-associated spondyloarthropathy in which inflammation begins at tendon and ligament entheses rather than the synovium, and the body's attempt to heal that inflammation lays down new bone that fuses the spine.

A granulomatous vasculitis of medium and large arteries that narrows the cranial branches of the carotid, threatening irreversible blindness within hours unless high-dose steroids are started the moment it is suspected.

A crystal arthritis in which chronically raised urate exceeds its solubility, deposits as monosodium urate crystals in cool peripheral joints and triggers explosive innate inflammation, treated acutely by damping inflammation and long-term by lowering urate.

Pain from the spine's muscles, discs and facet joints is usually a benign, self-limiting mechanical process, but the same anatomy can be compromised by fracture, infection, malignancy or nerve root/cauda equina compression, so every assessment is really a search for the minority who need urgent action.

A mechanical disease in which cartilage breakdown outpaces chondrocyte repair, leaving a failing joint that remodels bone and hurts most with the use that drives the wear.

A silent imbalance in which bone resorption outpaces formation, thinning and weakening the skeletal microarchitecture until a trivial force is enough to fracture it.

An inflammatory disorder of the shoulder and hip girdle synovium and periarticular structures in older adults, producing bilateral proximal pain and stiffness that resolves dramatically with corticosteroids, and closely linked to giant cell arteritis.

An autoimmune synovitis in which loss of tolerance to self-antigens drives a chronic inflammatory pannus that erodes cartilage and bone, symmetrically, from the small joints inward.

A joint-destroying emergency in which bacteria seed the synovium and, unrestrained by a poor local immune barrier, trigger a bacterial-and-host enzymatic assault that can destroy cartilage within days.

A multisystem autoimmune disease in which loss of tolerance to nuclear antigens generates immune complexes that deposit wherever they lodge, igniting complement-driven inflammation in the skin, joints, kidneys, serosa and brain alike.