Histoplasmosis
Revision as of 20:53, 30 November 2014 by Charleyrandazzo (talk | contribs) (Created page with "==Background== *Fungal infection caused by Histoplasma capsulatum *Endemic to the Ohio, Missouri, and Mississippi River valleys in the United States ==Clinical Features== ===A...")
Background
- Fungal infection caused by Histoplasma capsulatum
- Endemic to the Ohio, Missouri, and Mississippi River valleys in the United States
Clinical Features
Acute Pulmonary Histoplasmosis
- 90% asymptomatic, and usually self-limited
- Fever/chills
- Headache
- Malaise
- Myalgias
- Abdominal pain
- Joint pains
- Dyspnea
- Cough
- Hemoptysis
- Hilar/mediastinal lymphadenopathy
Chronic Pulmonary Histoplasmosis
- Mostly older patients with underlying lung disease
- Cough
- Weight loss
- Fever
- Malaise
- Sometimes hemoptysis, sputum production, dyspnea
- CXR may show:
- Upper lobe infiltrates
- Fibrosis, scarring
- Cavitations
Progressive Disseminated Histoplasmosis
- Seen in immunocompromised patients
- Acute form: fever, cough, weight loss, malaise, dyspnea, +/-CNS involvement
- Subacute form: wide variety of symptoms depending on affected organ system
- Chronic form: constitutional sx
Mediastinitis
- Enlarged lymph nodes undergo necrosis
- This leads to granulomatous mediastinitis
Differential Diagnosis
- Aspergillosis
- Blastomycosis
- Carcinoid Lung Tumors
- Chlamydial Pneumonias
- Coccidioidomycosis
- Legionella pneumonias
- Lung Cancer, Small Cell
- Lymphoma, Mediastinal
- Mediastinal Cysts
- Mycoplasma Infections
- Pancoast Syndrome
- Pneumococcal Infections
- Pneumocystis Carinii Pneumonia
- Pneumonia, Aspiration
- Pneumonia, Bacterial
- Pneumonia, Fungal
- Pneumonia, Viral
- Sarcoidosis
- Tuberculosis
Workup
- CBC (mild anemia in chronic disease)
- Alkaline phosphatase (elevated in disseminated and chronic disease)
- LDH (elevated in AIDS patients with disseminated disease)
- Sputum cultures
- Blood cultures
- Antibody testing
- Serum/urine antigen testing
- CXR
- Further imaging if concerned for specific organ involvement in disseminated disease (head CT, abdominal CT)
Treatment
Acute Pulmonary Histoplasmosis
- Do not treat if asymptomatic
- Itraconazole x 6-12 weeks
- Severe disease: Amphotericin B x 1 week then Itraconazole x 1 year
Chronic Pulmonary Histoplasmosis
- Itraconazole x 1 year
Progressive Disseminated Histoplasmosis
- See above medical therapy
- Surgical intervention may be needed for some end organ involvement
Sources
emedicine medscape