Imaging manifestations of cat-scratch disease.

Cat-scratch disease affects an estimated 22,000 people in the United States each year, more than half of whom are children or adolescents [1]. It is caused by Bartonella henselae, a gram-negative bacillus usually introduced by the scratch of a cat [2]. In the past, diagnosis was made if three of the following four criteria were met: (1) history of cat exposure with inoculation, (2) positive skin test: (3) absent laboratory and histopathologic evidence of other diseases, and (4) biopsy findings of granulomatous inflammation [3]. Recent identification of the causative organism has led to new diagnostic tests, including serum assays for B. henselae antibodies [4]. Although response of the disease to antibiotics is poor, spontaneous recovery generally occurs within months to years [3].