Images in Vascular Medicine. Rat bite fever: A rare case of critical limb ischemia.

Abstract

A 24-year-old female was transferred to our facility with a 3-month history of bilateral lower extremity hemiparesis, loss of bowel and bladder control, decubitus ulcers, unexplained weight loss, and fever of unknown origin. Upon arrival, she appeared emaciated with significant dysarthria and a fever of 102°F (38.9°C). She was unable to move her lower extremities on command. Magnetic resonance imaging revealed numerous infarcts in the brain and abdomen. An echocardiogram ordered to assess for the source of emboli revealed a 4.5-cm-long mitral valve vegetation along with severe mitral regurgitation (Panel A: arrow). Mitral valve tissue analysis revealed the bacteria Streptobacillus moniliformis, the causative agent for rat bite fever.1 The bacteria is acquired from bites, scratches, consuming contaminated food, or by handling infected rodents. Symptoms include fever, rigors, migratory polyarthralgias, headache, nausea, vomiting, sore throat, and severe myalgias.2 Prior to emergency mitral valve replacement, the right lower extremity was cool to touch along with delayed capillary refill and diminished pulses. The day after surgery, an arterial duplex demonstrated tardus parvus flow from the distal external iliac artery (EIA) to the ankle, suggestive of proximal occlusion (Panel B-1: peak systolic velocity; end Rat bite fever: A rare case of critical limb ischemia