Haverhill fever with spine involvement.

Haverhill fever and rat-bite fever are closely-related syndromes caused by Streptobacillus moniliformis. This infection is characterized by the abrupt onset of fever with rigors, myalgias, headache, polyarthritis, and rash. We report a case of infection with S. moniliformis that manifested as acute polyarthritis with involvement of the spine. To our knowledge, involvement of the spine has not been reported previously with this infection. Diagnosis can be particularly difficult in the absence of fever or obvious exposure to rodents, as in our case. A high degree of awareness is necessary to make the diagnosis of this potentially fatal infection, which is easily treatable.