A case of cat scratch disease neuroretinitis confirmed by polymerase chain reaction

BACKGROUND: Cat scratch disease neuroretinitis is caused by infection by Bartonella henselae. To demonstrate B. henselae infection, serologic examination is commonly used, but sometimes serologic examination is not adequate for correct diagnosis. Here we present a case of cat scratch disease neuroretinitis confirmed by polymerase chain reaction in addition to serologic examination. CASE: A 55-year-old woman, presenting with headache and high fever, had noticed visual disturbance. The best-corrected visual acuity in her right eye was 0.01. Meningitis, optic neuritis and retinitis were observed and she was treated with oral prednisolone. After repeated questioning, the patient remembered being scratched by a cat. Systemic examination focusing on B. henselae infection was conducted and B. henselae-specific immunoglobulin (Ig) G, but not IgM, was detected in both serum and cerebrospinal fluid. To confirm B. henselae infection, polymerase chain reaction (PCR) analysis using cerebrospinal fluid was performed and the presence of B. henselae-specific DNA was demonstrated. From these results, we diagnosed cat scratch disease neuroretinitis and treated the patient with minocycline hydrochloride together with prednisolone. Following this treatment regimen, the patient's condition improved, and the best-corrected visual acuity in her right eye increased to 0.6 five months after the onset.CONCLUSION: The PCR technique is useful to correctly diagnose cat scratch disease neuroretinitis, if patients exhibit marginal data on B. henselae-specific antibody titer.