Oh rats! Fever, rash and arthritis in a young woman

A 17-year-old girl presented with worsening right-sided hip and low back pain for 2 days. She had also experienced intermittent fevers and a recurring maculopapular rash over the past 2 weeks. Social history revealed the presence of three domestic rats living in the girl's home. Blood cultures returned positive for Streptobacillus moniliformis, the causative agent of rat-bite fever. Rat-bite fever often goes undiagnosed, as the clinical presentation is non-specific. Untreated, the infection can result in death due to sepsis or endocarditis. The bacterium is generally susceptible to penicillin antibiotics with full clinical recovery when treated in a timely and appropriate manner. After 4 weeks of intravenous antibiotics, our patient fully recovered without long-term sequelae.