Psoas abscess following extracorporeal shock wave lithotripsy.

Different studies have reported renal effects like swelling of parenchyma, subcapsular and intracapsular haematoma and perinephric fluid collections. These effects were usually transient and by 2-3 months returned to normal. We report an early complication of extracorporeal shock wave lithotripsy (ESWL). A patient with solitary renal calculus who had ESWL developed psoas spasm and became unwell with elevation of white cell count and erythrocyte sedimentation rate. Psoas abscess extending from renal hilum to the groin was diagnosed and drained surgically.