Grand Rounds—University Hospital of Wales: Focal myositis mimicking acute psoas abscessBMJ 1997; 314 doi: https://doi.org/10.1136/bmj.314.7083.805 (Published 15 March 1997) Cite this as: BMJ 1997;314:805
An unusual presentation of systemic lupus erythematosus
- J D Jessop, consultant rheumatologist,
- M H Pritchard, consultant rheumatologist,
- B D Williams, professor of rheumatology
- University Hospital of Wales Heath Park, Cardiff CF4 4XW
- Accepted 24 January 1997
We describe an unusual presentation of severe focal muscle inflammation in a young woman in whom the clinical and radiological findings were suggestive of a psoas abscess. Eighteen months after the onset of her illness, systemic lupus erythematosus was diagnosed.
A previously healthy 20 year old woman presented to her general practitioner with a two week history of severe pain in the lower back and thighs. Five weeks earlier she had developed neck pain followed by pain in her upper limbs, but these symptoms had resolved. She was treated initially for one week with erythromycin, failed to improve, and was then given aspirin. The development of abdominal pain, vomiting, and a swollen right knee prompted urgent referral to the rheumatology department. Her only other treatment was the contraceptive pill. She had been on holiday in Spain three months previously.
On examination she was pale, had a fever (38°C), and was systemically unwell. There was a pronounced lumbar lordosis, and both hips were flexed, any attempt at extension causing excruciating pain. There was tenderness and swelling of both thighs with an area of erythema overlying the tender muscles of the right thigh extending from the groin to the knee joint. A moderately sized effusion was present in the right knee. Sepsis was suspected clinically, and empirical treatment with flucloxacillin 1 g four times a day and cefuroxime 1.5 g three times a day was started.
Haemoglobin concentration was 96 g/l (normochromic normocytic pattern), white cell count 11.3x109/l, platelet count 467x109/l, erythrocyte sedimentation rate 58 mm in the first hour, aspartate aminotransferase 223 IU/l (normal 5-45 IU/l), and creatine kinase 946 IU/l (0-170 IU/l). Midstream urine specimens and four blood cultures were sterile. Synovial fluid from the right knee was clear with …