251.3 🩺 內科專科考前版

251.3.0.1 1⃣ Steroid Dosing in PJP

  • Prednisone 40 mg PO bid × 5 days
  • Then 40 mg PO qd × 5 days
  • Then 20 mg PO qd × 11 days
  • Total 21 days
  • Start within 72 hours of antibiotic
  • Equivalent IV methylprednisolone if PO not tolerated

251.3.0.2 2⃣ β-D-Glucan + PJP

  • Elevated in PJP + invasive Candida + Aspergillus + Fusarium
  • Not specific for PJP
  • Combined with clinical + imaging + sputum / BAL for diagnosis
  • Trend down with successful treatment
  • Cutoff > 200 pg/mL supportive

251.3.0.3 3⃣ Bronchoscopy + BAL Timing

  • BAL with immunofluorescence + silver stain
  • Often used when induced sputum negative or clinical suspicion high
  • BAL within 1-2 weeks of antibiotic start: organism still detectable
  • Beyond that: yield decreases

251.3.0.4 4⃣ PJP in Non-HIV Population — Increasing

  • Increasing recognition + cases in:
    • Solid organ transplant
    • Anti-CD20 therapy
    • Anti-TNF
    • Chemotherapy regimens
    • High-dose corticosteroids
  • Often more severe + higher mortality
  • Lower threshold for diagnosis + treatment

251.3.0.5 5⃣ Anti-CD20 + PJP Risk

  • Rituximab, ocrelizumab
  • Long B-cell depletion period (months-years)
  • Prophylaxis with TMP-SMX considered for extended periods
  • Especially in chemotherapy combinations (R-CHOP, RB)

251.3.0.6 6⃣ TMP-SMX Toxicity Management

  • Allergic rash: continue if mild + supportive; discontinue if severe (Stevens-Johnson, DRESS)
  • Marrow suppression: CBC monitoring
  • AKI: monitor Cr; reduce dose
  • Hyperkalemia: monitor K+; common
  • Desensitization protocols for prior allergy

251.3.0.7 7⃣ Pediatric PJP

  • HIV + immunodeficiency + leukemia + transplant
  • TMP-SMX prophylaxis routine in leukemia chemotherapy
  • Treatment same principles, weight-based

251.3.0.8 8⃣ 健保 / Taiwan

  • 健保 TMP-SMX widely covered
  • 健保 alternative agents for intolerance
  • ID + pulmonology + transplant ID consultation

251.3.0.9 9⃣ Future + Research

  • New diagnostics (PCR refinement, rapid antigen)
  • New treatment combinations
  • Better risk stratification for prophylaxis

251.3.0.10 10. Differential Pneumonia in Immunocompromise

  • PJP
  • CMV pneumonitis
  • Invasive aspergillosis
  • TB / NTM
  • Bacterial pneumonia (especially S. pneumoniae)
  • Viral pneumonia
  • Lung cancer
  • Pulmonary toxicity from drugs