For patients with penicillin allergy, oral tetracycline, 0.5 g four times daily, is acceptable. When therapy is administered promptly, cure can be anticipated. This spirillary, gram-negative, motile organism is found in the blood and in the peritoneal and lacrimal fluids of infected rats. The organism cannot be grown on artificial media. Its isolation from humans requires inoculation of blood or fluid from the primary cutaneous lesion into disease-free mice or guinea pigs.
Articular manifestations are uncommon.
A macular rash may occur. Biologic false positive test results for syphilis are common. Treatment is the same as for S. moniliformis rat-bite fever.