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- Discussion:
    - common acute infection which occurs most often in children;
    - is also common in immuno-compromised patients;
    - may arise from cat bite or scratch (more common w/ kittens), but may also be transmitted by flea bites;
    - up to 2 % of patients may have involvement of the CNS liver, spleen, lung, bone, and skin;

- Causative Agents:
    - Rochalimaea:
          - small gram-negative rods;
          - genus may belong to Rickettsiaceae or Bartonellaceae;
    - Afipia felis:
          - probably the main cause of cat stratch disease;
          - has been cultured from lymph nodes;

- Diff dx:
    - Kaposi's sarcoma;

- Clinical Findings:
    - fever, chills, malaise, headache, and anorexia;
    - firm subcutaneous nodules are common (2 to 6 cm in diameter);
    - skin lesions may be solitary but are usually multiple;

- Labs:
       - indirect fluorescent-antibody testing (serology);
       - enzyme immunoassay for the detection of IgG antibodies to R. henselae;

- Histology:
    - Examination of Skin Biopsy:
           - demonstrates lobular angioproliferation w/ plump "epithelioid" cells;
           - bacillary forms were identified in the lesions by Warthin-Starry staining;
           - neutrophils are common;
    - Histology of Nodes:
           - stellate caseating granulomas, microabscesses, and follicular hyperplasia;

- Treatment:
    - oral erythromycin 500 mg PO qid

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Cat scratch disease, bacillary angiomatosis, and other infections due to Rochalimaea.                                                            

Cat-scratch disease presenting as a paravertebral abscess. A case report.