Case history

A 53 year old self employed white business man was seen by the rheumatology unit at this hospital for the first time in May 1997. Over the last three years he had seen three different rheumatologists with an assymetrical arthritis, affecting mainly the right hand. This had been diagnosed as rheumatoid arthritis, based on the presence of rheumatoid factor in the blood and treated with 10 to 15 mg prednisolone a day for the last two years, as well as periods of treatment with sulphasalazine and methotrexate in the past. He presented with a painful right thumb and a painful restriction of left hip joint movement, which had gradually increased over the previous six weeks. His past history included a four year history of pustular psoriasis without apparent joint involvement and a history of low back and left groin pain 10 years ago, investigated elsewhere with a bone scan, plain radiography, and computed tomography of the left hip, with no cause found for the hip pain.

Examination revealed a well looking, afebrile man. He had obvious psoriasis on the feet with involvement of the toenails, no evidence of any deformities or active synovitis but had a painful right thumb carpometacarpal joint with crepitus on movement. Examination of his left hip joint revealed a non-pulsatile fullness in the left groin and painful restriction of left hip joint movements particularly flexion, abduction and external rotation, with virtually no internal rotation. There was no evidence of an inguinal hernia. The right hip joint had essentially full, pain free range of movement.

His C reactive protein measurement was within normal limits, the rheumatoid factor was increased at 405 IU/ml (normal < …