Bartonella: The Daily PANCE Blueprint
A 10-year-old boy presents with a swollen lymph node in his right axilla and fevers. Three weeks ago, he was scratched by a kitten. On physical exam, you note a 3 cm tender, enlarged lymph node in the right axilla, plus a small, healed scratch on his forearm. Which of the following is the most appropriate next step?
A. Start IV vancomycin
B. Reassure and observe only
C. Order serologic testing and begin azithromycin
D. Refer for lymph node biopsy
E. Order blood cultures for Bartonella
Answer and topic summary
The answer is C. Order serologic testing and begin azithromycin
Bartonella are gram-negative bacteria primarily transmitted through arthropod vectors and animal scratches or bites. Three species commonly cause human disease (Bartonella quintana, Bacillary angiomatosis, and Bartonella henselae) with Bartonella henselae being the most notable. It is the main cause of cat scratch disease. The classic presentation includes a papule or pustule at the inoculation site, followed by regional lymphadenitis developing 1–3 weeks later. Atypical manifestations may involve hepatosplenic lesions, neuroretinitis, osteomyelitis, or endocarditis. Diagnosis is based on clinical history and serologic testing (IFA or ELISA), as cultures are often insensitive and difficult. Management depends on the patient’s immune status and disease severity. In immunocompetent individuals, cat scratch disease may be self-limiting. For more significant lymphadenitis or persistent disease, azithromycin is recommended.
View blueprint lesson
Smarty PANCE Content Blueprint Review:
PANCE Blueprint Infectious Disease ⇒ Bacterial Disease ⇒ Bartonella