Case Studies

 Case 10.4 Ankylosing spondylitis

A 21-year-old man presented with acute pain and swelling of one knee. On examination, the joint was tender and restricted in movement. X-ray of the knee showed periarticular osteoporosis. On investigation, he had a raised erythrocyte sedimentation rate of 102mm/h, a mild anaemia (Hb 106g/l) but no detectable serum rheumatoid factor. The knee effusion was aspirated; the fluid contained a polymorphonuclear leucocytosis but no organisms or rheumatoid factor. No diagnosis was made at this stage but he was treated empirically with indomethacin; his arthritis improved.

Fifteen months later he developed an iritis in his left eye, low back pain and stiffness. His peripheral joints were normal but pain could be elicited in both sacroiliac joints. X-rays of his pelvis showed the classic changes of ankylosing spondylitis and tissue typing revealed that he was HLA-B27 positive. He has had intermittent backache over the last 5 years, although daily exercises have limited the stiffness. He has developed bony ankylosis between the lumbar vertabrae.