Of 145 patients with nonbacterial lymphadenitis observed over a period of 10 years, 115 had clinical cat scratch disease (CSD) with a positive cat scratch antigen skin test. In this group 86% had a typical benign course of CSD; the remaining 16 (14%) had an atypical form. These unusual forms were: Parinaud's oculoglandular syndrome in 7, encephalopathy in 3, atypical pneumonia in 2, and recurrent suppurative lymphadenopathy in 1. Two typical cases occurred after a dog scratch or bite, and one after a monkey scratch.
The disease was most prevalent in late fall and early winter; 80% of patients were under age 20 years. Primary lesions were detected in 55%, node suppuration occurred in 26%, and lymphadenopathy lasted 2 weeks to 2 months in most patients. Symptoms were absent in 35% of cases. Fever occurred in 26%, and exanthem was present in 4%. Lymphadenopathy was most common in the extremities (57%), and head and neck (43%). Cat scratch antigen was found to be a reliable diagnostic skin test. A negative test was found in 98% of control patients; a positive test was found in 94% of patients who were clinically suspected to have CSD and a history of cat scratch.
Management consisted of reassurance, symptomatic therapy, and closed aspiration of enlarged nodes if suppuration occurred. Antibiotics were not effective. The disease is self-limited and has an excellent prognosis in the majority of patients. An etiologic agent could not be isolated in this study. Until the causative agent is known, it will be difficult to carry out preventive measures.
