Cat scratch disease (CSD), also known ascat scratch fever,Teeny's Disease,inoculation lymphoreticulosis, andsubacute regional lymphadenitis, is a usually benign infectious disease caused by the intracellular bacterium Bartonella henselae. It is most commonly found in children following a scratch or bite from a cat within about one to two weeks.

Signs and symptoms

Manifestations of cat scratch disease can be divided into classic and atypical.

Classic cat scratch disease presents as tender and swollen regional lymph nodes, a condition referred to as regional lymphadenopathy. There may be a papule at the site of initial infection. While some patients have fever and other systemic symptoms, many do not. Other associated complaints include headache, chills, backache and abdominal pain. It may take 7 to 14 days, or as long as two months, before symptoms appear. Most cases are benign and self-limiting, but lymphadenopathy may persist for several months after other symptoms disappear. In general, the prognosis is favorable. In temperate climates, most cases occur in autumn and winter. The disease usually resolves spontaneously, with or without treatment, in one month. In immunocompromised patients more severe complications sometimes occur.

Atypical cat scratch disease takes several different forms depending on organ systems involved. Atypical forms of disease are becoming increasingly recognized in clinical practice.

Parinaud's oculoglandular syndrome is a granulomatous conjunctivitis with concurrent swelling of the lymph node near the ear.

Optic neuritis, involvement of the retina, and neuropathy can also occur.

Bacillary angiomatosis is caused by Bartonella henselae, the causative organism of cat scratch disease. It is primarily a vascular skin lesion that may extend to bone or be present in other areas of the body. In the typical scenario, the patient has HIV or another cause of severe immune dysfunction.

Bacillary peliosis is a condition that most-often affects patients with HIV and other conditions causing severe immune compromise. The liver and spleen are primarily affected, with findings of blood-filled cystic spaces on pathology
 

Acute encephalopathy (generalized dysfunction of the brain) can occur. The New York Times Magazinedescribed a case, presenting as a meningitis, with fever, headache, and impaired vision (due to swelling of the optic nerves). Despite the severity of initial presentation, patient outcome can be favorable.

Enlarged spleen and sore throat can also occur in rare cases. Sclerotic bone lesions can also occur.