Cat-scratch disease and related clinical syndromes.

Bartonella (Rochalimaea) henselae is a common cause of cat-scratch disease. This newly identified bacterium is also the cause of several other clinical syndromes, including bacillary angiomatosis, bacillary peliosis hepatitis and splenitis, and acute and relapsing bacteremia. A high percentage of young cats carry B. henselae. Fortunately, serious complications of B. henselae infections are rare in immunocompetent patients. Cat-scratch disease is usually a self-limited illness that does not necessarily require antibiotic therapy. Severe or persistent cases respond well to several antibiotics, including erythromycin and doxycycline. Cat-scratch disease should be included in the differential diagnosis of serious neurologic disease, particularly when regional lymphadenopathy develops suddenly in a previously healthy patient who owns a cat. Treatment of uncomplicated central nervous system disease is generally supportive. Antibiotic therapy is reserved for patients with atypical or severe involvement, including encephalopathy and retinitis. Other internal and cutaneous manifestations of B. henselae infection have recently been described. These potentially life-threatening infections respond well to antibiotic therapy, even in immunocompromised patients.