1 infec 69 - tabish60102

[ArchivalUser]

A 42-year-old man with HIV infection is evaluated because of a 5-week history of night sweats and weight loss of 2.2 kg (5 lb). He moved to New York City from his home in the Dominican Republic 3 months ago, when he started highly active antiretroviral therapy. His CD4 cell count before starting antiretroviral therapy was 240/µL (0.24 × 109/L). Following initiation of treatment, his CD4 cell count rose to 350/µL (0.35 × 109/L) and his plasma HIV RNA viral load fell from 500,000 copies/mL to an undetectable level. The patient takes no other medications.

Physical examination is normal except for an enlarged right cervical lymph node. A chest radiograph is normal. The lymph node is subsequently excised and stains positive for acid-fast bacilli.

Which of the following is the most likely diagnosis?

A Mycobacterium avium complex infection
B Mycobacterium marinum infection
C Mycobacterium kansasii infection
D Mycobacterium tuberculosis infection
E Immune reconstitution inflammatory syndrome

[ArchivalUser]

cc?

[ArchivalUser]

is it c

[ArchivalUser]

ddd?

[ArchivalUser]

(Correct Answer = D)
Key Point
The development of focal lymphadenitis in a patient with HIV infection is most commonly caused by mycobacteria, Streptococcus species, or Staphylococcus species.

This patient most likely has focal lymphadenitis caused by Mycobacterium tuberculosis. Localized lymphadenitis in patients with HIV infection is most commonly caused by pyogenic bacteria (i.e., Streptococcus or Staphylococcus species), Mycobacterium tuberculosis, Mycobacterium avium complex, or Mycobacterium kansasii infection.

The key to the diagnosis in this patient is the CD4 cell count before and after initiating antiretroviral therapy. His lowest known CD4 cell count before beginning therapy was 240/µL (0.24 × 109/L), which is well above the level (usually