Cat-Scratch Disease(CSD) or cat-scratch fever is caused by Bartonella henselae bacteria, commonly found in cat fleas or ticks. The organism enters the body typically through broken skin caused by scratch or bite by infected cat. Saliva of diseased cat can be infectious as well if allow contact with unhealed wound or mucous surfaces such as eyes, mouth, and nose. In the United States, about 40% of cat population is compromised but they are rarely sickened by the organism. Kittens under the age of 15 months are more likely to carry the Bartonella bacteria than older cats.
The first symptom of cat-scratch fever is usually reddened bumps or blisters at bite or scratch points, and likely fever. Within a week to three weeks after infection, lymph nodes closest to the injury points may become tender and swollen with fluid. This is known as regional lymphadenopathry. CSD-caused lymphadenopathy is most commonly found in the arms, neck, or jaw area, but may also occur around the ear or near the groin if close to point of injury. In some cases, fluid may leak from particularly swollen lymph nodes. Patients likely to exhibit some degree of reduced appetite, lethargy and bodily aches or soreness. Patients may also experience chills, arthritis, abdominal pain, and backache. Medical examination may reveal enlarged spleen or liver.
Most cases of cat-scratch disease pose no long term ill effects and the infection usually run its course in four to five weeks. However, swollen lymph nodes may linger for a few months even after other symptoms have fully resolved. A CSD patient usually obtains long-term immunity from the disease after full recovery.
Although generally perceived as benign, in rare occasions, especially in patients with much weakened immune system, CSD can open the channel to the development of severe skin lesion affecting the bone, serious cardio-vascular, or neurologic complications affecting brain, heart, eyes, and other internal organs, requiring extensive treatment.