Cat scratch disease

Cat scratch disease (CSD) is a bacterial infection that primarily affects the lymph nodes. It is typically caused by the bacteria bartonella ( Bartonella henselae ). It is usually transmitted by being scratched or bitten by a cat, but rarely, no scratch or bite is involved. Symptoms frequently include the formation of a small bump at the site of the scratch or bite, followed by fever and swollen lymph nodes (lymphadenopathy) within 1-3 weeks. Lymphadenopathy commonly resolves on its own within a few months, but in some cases it may persist for up to 2 years. People with weakened immune systems (and less commonly, people with healthy immune systems) may develop more widespread disease and additional symptoms or neurological complications, which can be severe. In most cases, particularly in children and adolescents, having CSD once means that it cannot occur again. The recurrence of symptoms months after disease onset has been reported in a few adults with CSD. Treatment in mild or moderate cases typically involves medicines or strategies to improve symptoms, such as using fever reducers, pain relievers, or local heat over the affected lymph node(s). In more severe or systemic cases, management may involve lymph node aspiration and/or antibiotics.

Rare complications of Bartonella henselae infection may include inflammation of the brain (encephalopathy), inflammation of the retina and optic nerve of the eye (neuroretinitis), and acute or chronic bone infection (osteomyelitis). A systemic illness characterized by lesions throughout the body (bacillary angiomatosis) and an eye problem similar to pink eye (Parinaud oculoglandular syndrome) may also occur.

People with immunocompromised conditions, such as those undergoing immunosuppressive treatments for cancer, organ transplant patients, and people with HIV/AIDS, are more likely than others to have complications of cat scratch disease.