Abstract

Ankylosing Spondylitis (AS) is a chronic inflammatory disorder that primarily affects the axial skeleton. Prevalence rate is 0.5 – 1% and is strongly associated with HLA B-27. It can also affect peripheral joints like hip, knee, shoulder etc. Extra skeletal manifestations may include anterior uveitis, aortitis, irritable bowel syndrome etc. Muscle involvement in AS is uncommon. Whether AS also involves muscles primarily remains disputed. Several factors associated with the disease (chronic inflammation, multiple enthesopathies, muscle stiffness and bone lesions) could be responsible for this not fully understood aspect of Ankylosing Spondylitis. Here we report a case of unusual muscle atrophy in a patient with Ankylosing Spondylitis and its possible pathogenic mechanisms.

Key words: Ankylosing Spondylitis, Muscle atrophy, HLA B-27