Diagnostic and therapeutic challenges raised by atypical forms of cat-scratch disease

Atypical presentations of cat-scratch disease (CSD) can raise diagnostic di fficulties because of the lack of specificity of the diagnostic criteria fo r this condition. The specific intradermal skin test is unsafe. Histologica l findings lack specificity, and serological tests are conclusive only when they are positive. Bartonella henselae is the most common cause of SD, alt hough some forms may be due to Afipia felis or Bartonella quintana. Watchfu l waiting is appropriate in uncomplicated forms of CSD, since they resolve spontaneously. Antimicrobial therapy may expedite recovery from atypical, p rolonged, or systemic forms, although their in vivo efficacy varies widely.