Bartonella henselae causes a transient infection in kittens and their fleas but may enter a carrier state. Despite the name “cat-scratch” disease, infection may be transmitted to humans by a cat bite or lick or by contact with a cat’s fleas. Human-to-human transmission is not known to occur. Local infection causes a granulomatous reaction.
Unilateral granulomatous conjunctivitis with one or more raised or flat gelatinous, hyperemic, granulomatous lesions develops on the superior or inferior tarsal conjunctiva, fornix, or bulbar conjunctiva about 3–10 days after inoculation. Either concurrently or 1–2 weeks later, ipsilateral regional preauricular and submandibular lymph nodes, and occasionally cervical nodes, become firm and tender. Approximately 10%–40% of the nodes enlarge and become suppurative. Mild systemic symptoms of fever, malaise, headache, and anorexia develop in about 10%–30% of patients, with severe, disseminated complications—including encephalopathy, encephalitis, thrombocytopenic purpura, osteolysis, hepatitis, and splenitis—occurring in approximately 2% of CSD patients. Optic neuritis and neuroretinitis have been reported.
Serologic testing is the most cost-effective means of diagnosing typical CSD. Antibodies to B henselae can be detected by indirect fluorescent antibody testing or by enzyme immunoassay. The enzyme immunoassay for B henselae is more sensitive than the indirect fluorescent antibody test and is available from specialty laboratories. The skin test antigen for CSD is neither commercially available nor standardized. Atypical CSD is best approached by combining serologic testing with culture or PCR.
The ideal treatment has not yet been determined. Various antibacterial treatment regimens have reported success. Suggested agents generally include azithromycin, erythromycin, or doxycycline. Rifampin is often used as an adjuvant. Responses to trimethoprim-sulfamethoxazole and fluoroquinolones have also been reported but appear to be inconsistent.
Birnbaum AD, Tu EY. Parinaud’s oculoglandular syndrome. In: Tasman W, Jaeger EA, eds. Duane’s Clinical Ophthalmology. Vol 4. Philadelphia: Lippincott Williams & Wilkins; 2011.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.