Abscesos piógenos y tuberculosos del músculo psoas

Abstract

Objectives 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. Patients and 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.