Fast Five Quiz: Pets and Human Health Risks

Richard H. Sinert, DO


May 27, 2022

Cat scratch disease, also known as cat scratch fever or subacute regional lymphadenitis, is a bacterial infection that affect the lymph nodes that drain the sites of inoculation. Bartonella henselae, a gram-negative rod, is considered the principal etiologic agent. Cat scratch disease one of the most common causes of chronic lymphadenopathy in children and adolescents.

Patients usually have a history of sustaining a scratch or bite from a cat (typically a kitten). Transmission can occur by petting alone with subsequent self-inoculation via a mucous membrane, skin break, or conjunctiva. Most patients develop one or more 3-mm to 5-mm, red-brown, nontender papules at the site of inoculation 3-10 days after the bacteria are introduced. These primary lesions last for 1-3 weeks, then recede as lymphadenopathy appears. In most individuals, the disease spontaneously resolves within 2-4 months.

Learn more about cat scratch disease.


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