Ankylosing Spondylitis

Ankylosing spondylitis is a type of chronic arthritis that mainly affects the spine and the joints where the spine meets the pelvis. It causes inflammation in these areas, leading to pain and stiffness, especially in the lower back and hips. Over time, this inflammation can cause the bones in the spine to fuse together, reducing flexibility and causing a hunched posture. The condition primarily affects young adults and is more common in men. It can also involve other parts of the body such as the eyes, causing uveitis, and sometimes the heart and lungs. The symptoms often improve with exercise but worsen with rest.

Ankylosing spondylitis is a chronic inflammatory disease characterized by inflammation of the axial skeleton, particularly the sacroiliac joints and spine, leading to progressive ankylosis and loss of spinal mobility. It is classified as a seronegative spondyloarthropathy strongly associated with the HLA-B27 gene. The pathogenesis involves immune-mediated inflammation targeting entheses, the sites where ligaments and tendons attach to bone. Clinically, it presents with inflammatory back pain, morning stiffness, and reduced spinal flexibility. Extra-articular manifestations include acute anterior uveitis, aortic regurgitation, and restrictive lung disease due to chest wall involvement. Radiographically, sacroiliitis and syndesmophyte formation are hallmark findings. The disease typically begins in late adolescence or early adulthood and has a chronic progressive course.