Cat Scratch Disease

Cat scratch disease (CSD) as the name suggests, is a disease that spreads through contact with cats. It occurs when a person is bitten or scratched by an infected cat or, when he comes in contact with an infected cat’s saliva or broken skin.

The disease was first described in 1889 by Henri Parinau in the French medical literature, but it took Dr. Robert Debré in 1931 to initially recognize cat as the causative vector for this illness. Dr. Debre also coined the term “cat scratch disease”.


More than fifty years later, in 1985, Bartonella henselae, a gram –negative bacillus, was identified as the primary causative agent for CSD.

Other factors that are implicated in causing CSD include dog and monkey bites, thorns, pins and splinters. Cat fleas are also implicated as they are capable of transmitting B henselae between cats. However, there does not exist any evidence of transmission of the bacteria from cat fleas to humans.

Ticks and other biting flies have also been recently reported as potential vectors.

No report of human to human transmission has been cited so far.

During the onset of cat scratch disease there is an incubation period of 3-12 days and this is followed by the development of pustules at site of scratch.

Painful lymph node swelling (lymphadenopathy) may be observed, quite close to the inoculation site,within 2-3weeks of coming in contact with the infected cat. In some cases the lymph node may form a fistula and begin to leak fluid.

Regional lymphadenopathy is seen in approximately 90% of patients and it is usually this symptom that prompts them to seek medical attention.

Although infrequent, CSD is a common cause of chronic lymph nodes in children. Approximately 80% of those affected are below the age of 21 years.

CSD is a self-limiting disease with a good prognosis, even in those who present with severe symptoms. In those who are healthy, the condition often resolves by itself in about 2-5 months.