Ankylosing spondylitis presenting with discitis.

Ankylosing spondylitis is not an uncommon disease worldwide, yet is relatively rare in Bahrain. There is a typical pattern of joint involvement in cases of ankylosing spondylitis, but the presentation of discitis is rare. We present a case of a patient presenting with backache and was diagnosed to have discitis. The diagnosis of ankylosing spondylitis was made only after he was found to be Human Leukocyte Antigen-B27 positive. This is the first case report of ankylosing spondylitis presenting as discitis in Bahrain.