Arthritis in cat scratch disease: an unusual manifestation.

Cat scratch disease (CSD) is a zoonosis caused by Bartonella henselae, which is usually transmitted to humans through scratches or bites from infected cats. It is primarily a disease of children and adolescents, although it can affect individuals of any age. In approximately 10% of cases, patients can present atypical manifestations that may involve the musculoskeletal system. Herein, we report a case of a healthy 51-year-old man that developed low-grade fever and regional lymphadenopathy, followed by erythema nodosum and oligoarthritis. He had been scratched and bitten by his cat before the onset of symptoms. The diagnosis was confirmed serologically by the presence of high titers of specific IgG antibodies. Bartonella henselae was also detected in the blood of the owner's cat by PCR and DNA sequencing.