title: [Pyogenic and tuberculous abscesses of the psoas muscle].
abstract: OBJECTIVE
  To describe the clinical characteristics of patients with abscess on the psoas muscle (PA) and to identify the possible differences existing between pyogenic and tuberculous etiologies.
  
  
  METHODS
  A retrospective review of patients diagnosed of PA in one hospital was conducted (1983-2009). Two groups were established, that is pyogenic and tuberculous, and the clinical findings, analyses and evolution were compared.
  
  
  RESULTS
  Thirty PA were included, 83% pyogenic and 17% tuberculous, average age 53 years. On 9 occasions, 30% were primary and on 21 occasions, 70% secondary (to skeletal pathology in 8, to urological in 8 and to gastrointestinal in 8). No clinical differences were observed between both groups. Pyogenic and tuberculous etiologies were differentiated analytically through leukocyte values (13,871 vs. 8,560/mm(3), p=0.018), hemoglobin (11 vs. 14 g/dL, p=0.008) and erythrocyte sedimentation rate (ESR) (108 vs. 17 mm/h, p<0.0001). Abscesses were diagnosed by computed tomography (CT) in 29 patients (97%) and by magnetic resonance in 1 (3%), both with a diagnostic sensitivity of 100%, as opposed to 50% for ultrasound scanning. Left laterality was less frequent in pyogenic abscesses (44% vs. 100%, p=0.031). The blood cultures were positive in 22% and abscess pus culture in 82%. Gram negative bacilli, Streptococcus spp. and S. aureus were the most frequent isolations. A total of 67% were drained: transcutaneously 50%, surgically 13% and both techniques 3%. Two patients died (7%), both with pyogenic abscess.
  
  
  CONCLUSIONS
  Secondary pyogenic abscesses constitute the most frequent PA group. CT is the diagnostic procedure of choice. Leukocytosis, anemia, raised ESR and right laterality suggest pyogenic etiology. Transcutaneous drainage is substituting surgical drainage and also makes it possible to obtain diagnostic samples.
authors: Servicio de Medicina Interna, Hospital Universitario Puerta de Hierro-Majadahonda, Madrid, España. pablo.garcia.montero@gmail.com
authors: P
authors: P
authors: García Montero
authors: P
authors: P
authors: Laguna del Estal
authors: M
authors: M
authors: López-Cano Gómez
authors: A
authors: A
authors: Castañeda Pastor
authors: M
authors: M
authors: Gil Navarro
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D016905:Gram-Negative Bacterial Infections / Q000175:diagnosis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016659:Psoas Abscess / Q000175:diagnosis* / Q000382:microbiology; D012189:Retrospective Studies; D013203:Staphylococcal Infections / Q000175:diagnosis*; D013290:Streptococcal Infections / Q000175:diagnosis*; D014376:Tuberculosis / Q000175:diagnosis*; D055815:Young Adult