In the United States, roughly 22,000 cases of CSD are diagnosed annually, with 2000 resulting in hospital admissions. Over 90% of individuals with the illness report some form of contact with cats, often kittens. The male:female ratio is 3:2. In 80% to 90% of cases, patients are younger than 21 years (7).

TABLE 2 Cat-Scratch Disease: Key Points


Benign and self-limited infection with a course lasting 6-12 wk

Bartonella henselae usually introduced into host via scratch from the claw or tooth of a kitten younger than 6 mo of age

Pathophysiology of CSD

Gram-negative bacteria found in cat saliva for several months after cat infection, though generally the cat reservoir is asymptomatic

Fleas act as the vector of transmission between cats

Human-to-human transmission does not occur


After an incubation of 7-12 days after a cat scratch or bite, skin lesions develop followed by tender regional lymphadenopathy

Half of patients report low-grade fevers and malaise

In most patients, the lymphadenopathy ranges from 1-5 cm; while the majority of lesions regress over 2-6 mo, they may last for as long as 2 yr. Suppuration is seen in approximately 10% of cases.

In the head and neck, atypical manifestations of CSD appear in up to 14% of patients, specifically Parinaud's oculoglandular syndrome (6%), encephalopathy (2%), and osteomyelitis (0.3%).


Current diagnostic options include the Bartonella serology, the B. henselae IFA test utilizing fluid aspirate or tissue from an affected lymph node, a lymph node biopsy, or a CSD skin test


In the immunocompetent host, CSD is not a serious illness and does not require treatment beyond reassurance


After an episode of CSD, healthy individuals usually develop lifelong immunity preventing reinfection

In children with normal immune systems, spontaneous healing with full recovery is the norm, usually with complete resolution of lymphadenopathy after 2-6 mo

Abbreviations: CSD, cat-scratch disease; IFA, indirect fluorescence antibody.

Untreated, CSD is a benign and self-limited infection with a course lasting 6 to 12 weeks (7). The principal clinical feature of CSD is tender regional lymphadenopathy, typically in the head and neck, as well as axillary and inguinal regions. Affected lymph nodes may be suppurative (7,8). A primary cutaneous lesion (typically a 0.5-1 mm papule or pustule) at the site of cat bite or scratch is reported from 25% to 60% of cases (8). Approximately 75% of patients report a bite or scratch to the head, neck, or upper limb. After an incubation period of 3 to 30 days (usually 7-12 days) after the injury, the skin lesions develop and precede lymphadenopathy by one to two weeks. Low grade fevers and malaise accompany lymphadenopathy in up to half of patients with CSD (9). Other studies have reported nausea and vomiting, sore throat, anorexia, headache, and splenomegaly, while brief nonspecific maculopapular eruptions, erythema nodosum, figurate erythemas, and thrombocytopenic purpura have also been described.

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