Purpose: Cat scratch disease is a mild pathology but diagnosis often remain difficult.
Methods: A retrospective study has been conducted by the department of infectious diseases at the University hospital in Angers. Between January 1994 and October 1998, 26 observations were recorded providing the presence of three criteria out of four among the following: contact with a cat, clinical presentation and its favorable course, absence of any other cause noticed, and the presence of either a positive serology or a positive PCR, or the examination of a suggestive pathology.
Results: Fourteen men and 12 women were concerned. From a clinical point of view, the inoculation lesion was observed six times, all patients showed at least one adenopathy during their illness, 12 patients showed only an adenopathy without clinical signs. A surgical biopsy was carried out on nine patients and a diagnosis established. Bartonella henselae serology was done in all patients. Six presented a significant rate of IgG antibodies as early as the first dosage. A seroconversion was observed in four cases belatedly 1 to 2 months after the beginning of the symptomatology. The method's sensitivity was approximately 38%. A PCR search was accomplished in the pus obtained from a ganglionic puncture on 12 patients. It was positive seven times, which corresponds to a sensitivity of about 58%. In associating these two diagnostic criteria a sensitivity rate of nearly 92% was reached, the diagnosis not having been confirmed only in one case. The outcome proved to be favorable in all cases, with or without an antibiotic treatment.
Conclusion: The association of serology and PCR in the pus permits a certain diagnosis in the majority of the cases and avoids the more aggressive biopsy.