322.2 🩺 國考版

322.2.1 高頻考點

322.2.1.1 PCP

  • HIV CD4 < 200 (or other severe immunosuppression)
  • TMP-SMX treatment + prophylaxis
  • Adjunctive steroids if PaO2 ≀ 70 OR A-a gradient ≥ 35
  • HRCT: bilateral ground-glass perihilar sparing periphery

322.2.1.2 Aspergillus IPA

  • Halo sign → air crescent sign
  • Galactomannan (serum + BAL)
  • Isavuconazole or voriconazole first-line
  • Combination for severe
  • Surgical resection for cavitary / hemoptysis

322.2.1.3 Aspergilloma

  • Pre-existing cavity (TB, COPD bullae)
  • Antifungals limited efficacy
  • Surgery for hemoptysis

322.2.1.4 CAPA (COVID-Associated Pulmonary Aspergillosis)

  • ICU COVID patients
  • Steroids increase risk
  • Galactomannan
  • Voriconazole or isavuconazole

322.2.1.5 Mucormycosis

  • DKA, iron overload, neutropenia, COVID (CAM)
  • Non-septate broad 90° hyphae
  • Liposomal amphotericin + surgery
  • Reverse risk factors

322.2.1.6 Cryptococcus

  • HIV + CNS most common
  • Serum cryptococcal antigen
  • Pulmonary alone (immunocompetent): fluconazole
  • Severe / CNS: amphotericin + flucytosine → fluconazole

322.2.1.7 Endemic Mycoses Geography

  • Histoplasmosis: Ohio + Mississippi (bird/bat droppings)
  • Coccidioidomycosis: Southwest US (Arizona, California)
  • Blastomycosis: Mississippi + Ohio + Great Lakes
  • Paracoccidioides: Brazil
  • Talaromyces marneffei: SE Asia (HIV)

322.2.1.8 Histoplasmosis

  • Mild: observation or itraconazole
  • Severe: amphotericin → itraconazole 12 mo

322.2.1.9 Coccidioidomycosis

  • “Valley fever” = acute pulmonary + arthralgia + erythema nodosum
  • Severe / disseminated: amphotericin → fluconazole
  • Meningitis: fluconazole lifelong

322.2.2 易混淆比范

Fungal Infection Host Imaging Treatment
PCP HIV CD4<200, IS Bilateral GG perihilar TMP-SMX + steroids
Aspergillus IPA Neutropenia Halo sign, nodules Isavuconazole, voriconazole
Mucormycosis DKA, IO, COVID Reverse halo, infarction Amphotericin + surgery
Cryptococcus HIV Nodules, masses Amphotericin + flucytosine → fluconazole
Histoplasmosis Endemic + immune Mediastinal LAD Itraconazole or amphotericin
Coccidioides Southwest US Cavities, nodules Fluconazole or amphotericin
Talaromyces SE Asia + HIV Diffuse Amphotericin → itraconazole

322.2.3 Special Topics

322.2.3.1 Aspergillus Subtypes (HRCT)

  • Halo sign: early IPA
  • Air crescent sign: recovery (neutrophil return)
  • Tree-in-bud: bronchopulmonary aspergillosis
  • Aspergilloma: ball in cavity

322.2.3.2 β-D-Glucan

  • Pan-fungal marker
  • PCP + Aspergillus + Candida + others
  • Cryptococcus + mucormycosis NEGATIVE
  • Sensitivity 70-80%, specificity 70-80%

322.2.3.3 IRIS in HIV + Mycotic Infections

  • Worsening despite treatment + ART
  • Often Cryptococcus + Histoplasma
  • Continue therapy + steroids if severe