Arthritis and osteoblasts. Osteoclast activity can be directly induced by osteoblasts through the RANK/RANKL mechanism. Lupus is a common collagen vascular disorder that can be present with severe arthritis. Other features of lupus include a skin rash, extreme photosensitivity, hair loss, kidney problems, lung fibrosis and constant joint pain. Gout is caused by deposition of uric acid crystals in the joint, causing inflammation. There is also an uncommon form of gouty arthritis caused by the formation of rhomboid crystals of calcium pyrophosphate known as pseudogout. In the early stages, the gouty arthritis usually occurs in one joint, but with time, it
Reactive arthritis heel pain. Not all affected persons have all the manifestations. The clinical pattern of reactive arthritis commonly consists of an inflammation of fewer than five joints which often includes the knee or sacroiliac joint. The arthritis may be "additive" (more joints become inflamed in addition to the primarily affected one) or "migratory" (new joints become inflamed after the initially inflamed site has already improved). Reactive arthritis is an RF-seronegative, HLA-B27-linked arthritis often precipitated by genitourinary or gastrointestinal infections. The most common triggers are intestinal infections (with "Salmonella", "Shigella" or "Campylobacter") and sexually transmitted infections (with "Chlamydia trachomatis"). It most commonly