Cat-Scratch Disease

An acute infection caused by Bartonella henselae

Seen in children and young adults

It is transmitted from cats to humans as the result of a scratch or bite

Disseminated forms of the disease occur in immunocompromised patients, such as persons with late stages of HIV or solid organ transplant recipients

• Bacillary angiomatosis

• Peliosis hepatis

• Retinitis

Endocarditis can occur (usually due to Bartonella quintana)

A papule or ulcer will develop at the inoculation site within a few days in one-third of patients

Fever, headache, and malaise occur 1–3 weeks later

The regional lymph nodes become enlarged, often tender, and may suppurate

Lymphadenopathy resembles that resulting from neoplasm, tuberculosis, lymphogranuloma venereum, and bacterial lymphadenitis

Encephalitis occurs rarely

Clinical

Special cultures for Bartonella, serology (high antibody titer in an indirect immunofluorescence assay), nucleic acid amplification assay, or excisional biopsy, although rarely necessary, confirm the diagnosis

Lymph node biopsy revealing necrotizing lymphadenitis is not specific for cat-scratch disease

Usually self-limited, requiring no specific therapy

For bacteremia and endocarditis, a 6-week course of doxycycline (200 mg orally or intravenously in two divided doses per day) plus either gentamicin 3 mg/kg/day intravenously or rifampin 600 mg/day orally in two divided doses is effective

Disseminated forms of the disease (bacillary angiomatosis, peliosis hepatis, and retinitis) require a prolonged course of often double antibiotic therapy