Summary
Cat-scratch disease (CSD) is characterised by infectious conjunctivitis, transmitted by animals, associated with an intense reactive lymphadenopathy. It was first described in 1889 by H. Parinaud. The prevalence of CSD is approximately 6.6 (ranging from 1.8-9.3) cases per 100,000 individuals. The peak incidence seems to be situated between 30 and 50 years, 75 % of cases being reported during the cold period of the year, between September and April. The male-to-female ratio is 3:2. The clinical picture includes the lymphadenopathy, fever (38-41°C), fatigue, headaches, splenomegaly and cutaneous manifestations (transient maculopapular rash). Some atypical manifestations were also noted: neurological involvement with encephalitis or peripheral nerve involvement, ophthalmic involvement (Parinaud oculoglandular syndrome), lung involvement, cardiovascular involvement, hepatomegaly, thrombocytopenic purpura, and erythema nodosum. The pathogenic agent is a Gram negative bacillus, Bartonella henselae. The vectors responsible for the transmission of the disease are fleas, contamination occurring through a scratch or a bite from a cat or through the sting of an infected flea. In addition to the clinical picture, diagnosis is based on serological testing (indirect immunofluorescence or enzymatic immunoassay with titration of IgG or IgM antibodies), histopathological examination of lymphadenopathies showing features that are consistent but not patognomonic (nonspecific inflammatory infiltrates, granulomas, micro-abscesses) and polymerase chain reaction (PCR) on valvular or lymph node biopsies. Prognosis of CSD is excellent for immunocompetent patients, with spontaneous resolution in 90 % of cases. However, antibiotherapy is necessary in cases of immunodepression, as well as in cases with neurological and cardiac involvement. *Author: Orphanet (August 2006)*.
