Iliopsoas Abscess Caused by Streptococcus pyogenes: A Case Report

Abstract

There have been an increasing number of fatal infectious diseases caused by the so-called “flesh-eating bacteria”, one of which is Streptococcus pyogenes . So far, S. pyogenes has not been recognized as a cause of iliopsoas abscess. Here we report a rare case of iliopsoas abscess resulting from a S. pyogenes infection. A 64-year-old female with no past medical record was transferred to our hospital with a complaint of severe pain on the left side of her back. Upon arrival, cyanosis of the mouth and extremities was evident. An arterial blood gas analysis revealed metabolic acidosis. Laboratory analysis revealed liver and renal malfunction, as well as remarkably elevated C-reactive protein levels (29.18 mg/dL). Contrast-enhanced computed tomography revealed swelling of the left iliopsoas muscle. She was diagnosed with septicemia and multiple organ failure resulting from an iliopsoas abscess. She was admitted to the intensive care unit. Despite our efforts to treat her condition, including the administration of anti-bacterial drugs, a vasopressor drug, and dialysis treatment, her respiratory and cardiac conditions immediately worsened and she died 22 h after arrival. Blood culture obtained on arrival was positive for S. pyogenes . An autopsy performed after the consent of her family confirmed iliopsoas abscess on her left side. Microscopic findings revealed necrotizing fasciitis and myositis with the presence of Streptococcus inside the muscle. Thus, a diagnosis of necrotizing fasciitis and myositis caused by group A β-hemolytic Streptococcus was established. Little is known about iliopsoas abscess resulting from S. pyogenes infection. More awareness about this critical condition is needed, so that emergency clinicians can save patients from further progression of the disease. Clin Infect Immun. 2016;1(2):45-47 doi: https://doi.org/10.14740/cii15w