Ann Rheum Dis 2001;60:173–176 173 Ann Rheum Dis: first published as 10.1136/ard.60.2.173c on 1 February 2001. Downloaded from chronic illness and generalised symptoms of under imaging guidance, and microbial cul- systemic infection, such as prolonged fever, ture of the causative organism.57If abdominal LETTERS TO malaise, anorexia, weight loss, and anaemia.23 CT or MRI is unavailable, ultrasonography Pain with flexion and external rotation of may demonstrate the inflammatory mass.8 THE EDITOR the aVected hip is the most common physical Gallium-67 scanning may be useful in the finding.1–3 A tender palpable mass may be diagnosis of psoas abscesses and detection of found in the iliac fossa and inguinal area.23 concomitant infectious foci.9 DiVerential diag- Fifty per cent of patients have abdominal noses of psoas abscess include bacterial infec- tenderness, but guarding and rebound ten- tion of the hip, avascular necrosis of the hip, derness are uncommon.3 Because of the non- irritable hip, necrotising fasciitis of the psoas Primary psoas abscess specific pain location, the diagnosis of psoas muscle, pyelonephritis, pelvic inflammatory Primary psoas abscess is a rare infection with abscess may be delayed or missed. DiVeren- disease, retrocaecal appendicitis, S1 herniated an often vague and non-specific clinical pres- tiation between psoas abscess and hip pathol- disc, avascular necrosis, vertebral or pelvic 34 entation, especially in children. In Asia and ogy can be diYcult; however, prudent physi- osteomyelitis, and epidural abscess. These Africa 99.5% of all psoas abscesses are cal examination of the hip can be useful. With entities should be distinguishable upon the primary, compared with 61% in the United psoas abscesses there usually is no discomfort correlation of history, physical examination, on full flexion of the hip, whereas the States and Canada and 18.7% in Europe.12 laboratory tests, and imaging studies. presence of hip pathology typically elicits Approximately 70% of psoas abscesses occur The cause of primary psoas abscess pain.35 Laboratory studies are non-specific in patients younger than 20 years of age, with remains uncertain. Proposed mechanisms of and typically show leucocytosis, anaemia, a a male preponderance of 3:1.1 Fifty seven per psoas abscess formation include haematog- raised erythrocyte sedimentation rate, and, cent of psoas abscesses occur on the right enous spread from primary infectious foci or usually, normal urine analysis.236 side, 40% on the left side, and 3% bilaterally.3 local trauma with intramuscular haematoma Plain abdominal radiographs occasionally We present the following case and show the formation predisposing to abscess develop- define an outline of the inflammatory mass. 6 magnetic resonance imaging to emphasise ment. In secondary psoas abscess the most Chest radiographs may disclose minimal pleu- the presenting signs, symptoms, and findings commonly associated disorder is Crohn’s dis- ral eVusion or raised hemidiaphragm. An of this unusual infection. ease; other disorders include appendicitis, intravenous pyelogram may show deviation of colonic inflammation or neoplasm, disc A 13 year old white girl was in excellent the kidney and ureter. Barium studies may health until she developed a dull ache in the infections, and a variety of intra-abdominal or disclose bowel loop displacement and associ- retroperitoneal infections.1–4 Primary psoas superior posterior thigh without radiation. She ated gastrointestinal diseases.235However, the denied any direct trauma or excessive strenu- abscesses are caused by a single organism in most accurate diagnostic imaging is computed 87.5% of cases: primarily Staphylococcus ous activity. Over five days she developed pro- tomography scan (CT) or MRI, which typi- gressively severe, dull pain, localised to the aureus (88.4%), streptococci (4.9%), and cally show a low density lesion of the psoas Escherichia coli (2.8%).1 Blood cultures are posterior hip in association with fever to muscle and gas within the muscle itself.57 38.9°C, nausea, vomiting, and diarrhoea. She positive in 41.7%, usually for Staphylococcus There may be rim enhancement of the abscess aureus.1 In the past decade the majority of walked with a limp. Her past medical history wall with contrast medium injection. Defini- was non-contributory; she denied smoking, patients with a primary psoas abscess were tive diagnosis is made by fine needle aspiration intravenous drug users (86%) infected with alcohol, drug use, or sexual activity. The girl 7 was 1.52 m tall and weighed 70 kg. Vital signs the human immunodeficiency virus (57%). were normal; temperature rose to 38.9°C Treatment for primary psoas abscess in- cludes percutaneous drainage combined with within 24 hours of admission. A detailed gen- 10 eral physical examination was normal. Ab- systemic antibiotic administration. Surgical dominal and pelvic examinations were benign drainage is preferred for the patients in whom the psoas abscess is associated with underly- without organomegaly or peritoneal signs. 10 Stool for occult blood was negative. Muscu- ing bowel disease. With appropriate treat- ment, psoas abscess rarely results in death loskeletal examination was normal, with the 1 exception of the left hip which showed pain on (2.5%). Death from psoas abscess is associ- http://ard.bmj.com/ ated more commonly with inadequate or active and passive motion, particularly abduc- 1 tion and medial rotation. The range of motion delayed drainage, or both. Our patient of the hip was normal; there was no localised responded well to antibiotic treatment and warmth or palpation tenderness. The gait was recovered completely. antalgic for the left leg. T THONGNGARM Laboratory examination showed a white Department of Medicine, Siriraj Hospital, blood cell count of 15.2 × 109/l (77% Mahidol University, Bangkok, Thailand neutrophils/14% lymphocytes/8% monocytes) and on September 28, 2021 by guest. Protected copyright. and platelets were 415 × 109/l. An erythrocyte Division of Rheumatology and Molecular sedimentation rate was 115 mm/1st h (normal Immunology, <20 mm/1st h). Urine analysis disclosed trace Figure 1 Coronal magnetic resonance imaging University of Mississippi Medical Centre, blood and protein; the remainder of the scan of the abdomen showing abnormal signal Jackson, MS, USA laboratory tests were within normal limits. intensity in the inferior pole of the left psoas Blood and cervical cultures were negative. muscle (arrows). Note the proximity of the psoas R W MCMURRAY to the femoral head. Posteroanterior radiographic examination of Rheumatology Section/Medicine Service, the left hip was normal. Bone scan was normal. GV (Sonny) Montgomery VA Hospital Magnetic resonance imaging (MRI) of the and abdomen and pelvis showed grossly abnormal Division of Rheumatology and Molecular signal intensities of the left psoas muscle (figs 1 Immunology, and 2). Although a discrete abscess was identi- University of Mississippi Medical Centre, fied, fine needle aspiration under imaging Jackson, MS, USA guidance yielded no pathological material. Correspondence to: Dr R W McMurray, Division of Vancomycin was started empirically, based on Rheumatology and Molecular Immunology, L525 likely causative organisms. The patient defer- Clinical Sciences Building, University of Mississippi vesced, became ambulatory within one week, Medical Centre, 2500 North State Street, Jackson, and was discharged to complete an outpatient MS 39216, USA antibiotic course. This case demonstrates the manifestations of psoas abscess formation. The classical pre- 1 Ricci MA, Rose FB, Meyer KK. Pyogenic psoas abscess: worldwide variations in etiology. World senting symptoms of psoas abscess are pain, J Surg 1986;10:834–43. limp, fever, and psoas spasm.2–4 Pain is most 2 Gruenwald I, Abrahamson J, Cohen O. Psoas abscess: case report and review of the litera- commonly localised to the ipsilateral hip, but Figure 2 Cross sectional magnetic resonance occasionally radiates to the abdominal wall, ture. J Urol 1992;147:1624–6. imaging of the pelvis showing abnormal signal 3 Bresee JS, Edwards BS, Edwards MS. Psoas back, thigh, inguinal area, flank, knee, and intensity of the psoas closely approximating the abscess in children. Pediatr Infect Dis J calf.13 Patients may also present with a bladder (arrow). 1990;9:201–6. www.annrheumdis.com 174 Letters Ann Rheum Dis: first published as 10.1136/ard.60.2.173c on 1 February 2001. Downloaded from 4 el Hassani S, Echarrab el-M, Bensabbah R, Attaibi A, Kabiri H, Bourki K, et al.Primary psoas abscess. A review of 16 cases. Rev Rhum Engl Ed 1998;65:555–9. 5 Williams MP. Non-tuberculous psoas abscess. Clin Radiol 1986;37:253–6. 6 Isabel L, MacTaggart P, Graham A, Low B. Pyogenic psoas abscess. Aust N Z J Surg 1991; 61:857–60. 7 Santaella RO, Fishman EK, Lipsett PA. Primary vs secondary iliopsoas abscess. Arch Surg 1995;130:1309–13. 8 Chern CH, Hu SC, Kao WF, Tsai J, Yen D, Lee CH. Psoas abscess: making an early diagnosis in the ED. Am J Emerg Med 1997;15:83–8. 9 Kao PF, Tzen KY, Tsui KH, Tsai MF, Yen TC. The specific gallium-67 scan uptake pattern in psoas abscesses. Eur J Nucl Med 1998;25: 1442–7. 10 McAuliVe W, Clarke G. The diagnosis and treatment of psoas abscess: a 12 year review. Aust N Z J Surg 1994;64:413–17. Klippel-Feil syndrome in the prehispanic population Figure 2 (A) Atlas with a hypoplastic left arch; the lack of fusion of the anterior arch of the left of El Hierro (Canary foramen transversarium is also evident. (B) Left hemiatlas. Islands) with sharp, fine