Cat-scratch uveitis confirmed by histological, serological, and molecular diagnoses

To report a case of a cat-scratch uveitis caused by Bartonella henselae, which was confirmed by histology, serology, and polymerase chain reaction (PCR) methodology.

An iris nodule was biopsied from a 4-year-old child who was scratched by a kitten on the side of his face and developed redness of the eye associated with cervical lymphadenopathy. Sections of the iridectomy specimen were stained with hematoxylin-eosin, periodic acid-Schiff, and Warthin-Starry technique for histopathologic evaluation. Additionally, serologic tests and molecular diagnosis using B. henselae-specific PCR were performed.

Histopathologically, sections of the iridectomy specimen showed a zonal granulomatous inflammation with a central iris necrotic abscess surrounded by a mantle of epithelioid histiocytes and more peripherally by lymphocytes and plasma cells. The Warthin-Starry stain disclosed scattered short bacilli within the necrotic abscess morphologically compatible with B. henselae. Report of serologic tests for B. henselae disclosed a negative immunoglobulin G antibody (negative: less than 12) and a positive immunoglobulin M antibody of 18 (positive: greater than 15). Other serologic studies including Toxocara, histoplasmin, blastomycin, coccidioidin, aspergillin, and Chlamydia were all negative. PCR was positive for B. henselae DNA.

Our case showed a unilateral chronic granulomatous iritis with the histopathologic features compatible with CSD caused by B. henselae bacillus as demonstrated in the iris biopsy and confirmed by serology and PCR technique. This case is an example of a relatively rare uveal manifestation of CSD.