Introduction Cat scratch disease (CSD), a regional lymphadenitis affecting those lymph nodes draining dermal and/or conjunctival sites of inoculation, probably is the most common cause of chronic lymphadenopathy among children and adolescents. Adults account for only 10% to 20% of cases. It usually presents as a benign, self-limited disease involving tender regional lymphadenopathy that frequently has been present for 3 weeks or longer. In most cases the infection is preceded by a cat scratch or other close contact with a cat (generally an immature one). This infection's association with cat scratches was described first by Robert Debre in 1931. Since then, the spectrum of CSD has been expanded to include the presence of various skin rashes, such as erythema nodosum and erythema multiforme, ocular involvement, and constitutional symptoms such as fatigue and fever. In addition, many case reports of CSD have included descriptions of atypical clinical manifestations such as central nervous system involvement, arthritis, osteomyelitis, and severe chronic systemic disease. Most recently, two possible etiologic agents of CSD have been identified: a fastidious, pleomorphic gram-negative bacillus, Afipia felis, and a rickettsial pathogen named Rochalimaea henselae. Epidemiology CSD appears to occur worldwide and is seen in all regions of the United States. Cases may be seen sporadically all year long, but it appears to have a seasonal preference.