Neonatal psoas abscess simulating septic arthritis of the hip: a case report and review of the literature.

We report a newborn infant with psoas abscess caused by methicillin-sensitive Staphylococcus aureus. He was referred to our hospital with a history of hospital admission for hip septic arthritis without clinical improvement, and presented limited left hip motion, swelling on the groin and pain. A magnetic resonance imaging study revealed an abscess of the left psoas muscle. Surgical drainage and antibiotic treatment resulted in full recovery.