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
Neonatal-onset multisystem inflammatory disease involve the skin, joints, and central nervous system. All have a maculopapular urticarial skin rash that is often present at birth (75% cases). It is probably more correctly described as an urticarial-like rash. The presence of the rash varies with time, and biopsy of these skin lesions shows a perivascular inflammatory infiltrate including granulocytes. In about 35-65% of cases, arthritis occurs. Joint signs are variably expressed and can lead to transient swelling without sequelae between crises, or to unpredictable anomalies of growth cartilage and long bones epiphyses suggestive of a pseudo-tumour. Biopsies reveal hypertrophic cartilage without inflammatory cells. This most