245.4 📌 章末速蚘

245.4.0.0.1 Histoplasmosis
  • Histoplasma capsulatum — dimorphic fungus
  • Endemic: Ohio + Mississippi River valleys, Latin America
  • Exposure: bird + bat droppings, caves, old buildings
  • Asymptomatic 90%
245.4.0.0.2 Clinical Forms
  • Acute pulmonary: flu-like; severe with heavy exposure (ARDS)
  • Chronic pulmonary: COPD/emphysema + cavitary (mimics TB)
  • Disseminated: HIV CD4 < 100 + immunocompromise; pancytopenia + hepatosplenomegaly + LAP + oral ulcers + adrenal insufficiency
  • Fibrosing mediastinitis: rare severe late complication
245.4.0.0.3 Diagnosis
  • Urinary Histoplasma Antigen (90% sens for disseminated; rapid)
  • Serum antigen + antibody complementary
  • Culture (slow, gold standard)
  • Histology: small intracellular yeast in macrophages
  • Elevated LDH + ferritin in disseminated
  • Bone marrow biopsy high yield in disseminated
245.4.0.0.4 Treatment
  • Asymptomatic / mild acute: no treatment
  • Acute pulmonary symptomatic: itraconazole 200 bid × 6-12 wk
  • Chronic pulmonary: itraconazole × 12-24 mo
  • Disseminated severe: liposomal AmB 1-2 wk + itraconazole 12+ mo
  • CNS: higher-dose AmB + itraconazole × 12+ mo
  • HIV maintenance: until CD4 > 150 × 6 mo on ART
  • TDM for itraconazole (trough > 1.0 mg/L)
245.4.0.0.5 Special
  • POHS (ocular)
  • Adrenal insufficiency in disseminated
  • Mediastinal forms (fibrosing severe complication)
  • H. duboisii African — larger yeast, more cutaneous/bone
245.4.0.0.6 盧醫垫 hint
  • Ohio/Mississippi valley + acute flu-like + cave/demolition exposure → urinary Histo antigen
  • HIV CD4 < 100 + pancytopenia + adrenal lesions → disseminated histoplasmosis workup
  • Chronic cavitary pulmonary + COPD + endemic area → chronic histoplasmosis (vs TB)