Fungal Infections¶
Justin Smith
Histoplasmosis¶
Background¶
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Endemic to Ohio and Mississippi river valley
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Pulmonary infiltrate with hilar or mediastinal LAD, pulmonary nodule/cavitary lesion, pulmonary syndrome with erythema nodosum
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DDx: TB, malignancy, sarcoidosis (if considering sarcoidosis, rule out histoplasmosis as sarcoidosis treatment can induce disseminated histoplasmosis)
Evaluation¶
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Antigen (requires attending approval): For acute pulmonary histoplasmosis, 65% urine sensitivity, 69% serum sensitivity, and 83% sensitivity when co-tested. Thus, both serum and urine Ag are usually sent together
- Lower rates of positivity when disease is localized, versus diffuse throughout the lungs or disseminated.
- There are relatively high rates of cross-reactivity, where histoplasma antigen will be positive with blastomycosis; therefore, do not order blasto Ag if ordering histo Ag in MOST cases
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Serology: Consider Histoplasma Ab if evaluating for pulmonary disease
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Culture: most useful in chronic infections, sensitivity is low in acute/localized and may take >6 weeks to grow.
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Bronchoscopy: If clinical suspicion is high and work up negative, consider interventional pulmonology consult for consideration of bronchoscopy
Management¶
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Outpatient/Mild disease:
- Tx not required if symptoms \<4 weeks, initiate if symptomatic beyond 4 weeks
- Itraconazole: 200mg TID x3 days loading, then BID (adjusted by levels which are drawn 2 weeks post-start) for 6-12 weeks minimum
- Can use oral formulation or capsules (capsules require high acidity, give with food consumption or OJ or coke; do not use capsules if patient is on H2 blockers/PPI)
- Voriconazole, Posaconazole: used if not tolerating itraconazole or as salvage therapy
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Inpatient/Moderate to Severe Disease:
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Amphotericin: 1-2 weeks induction, followed by PO itraconazole for 12 weeks (total)
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Methylprednisolone: help to prevent ARDS with significant lung involvement
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Additional Information¶
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Complications: Pericarditis, arthritis/arthralgias with erythema nodosum, chronic cavitary lesions, fibrosing mediastinitis, broncholithiasis
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Disseminated Histoplasmosis:
- Typically found in immunocompromised populations
- Clinical presentations: FUO, weight loss, disseminated LAD, cutaneous manifestations, bone marrow suppression/pancytopenia, liver enzymes elevation, various solid organ involvement on imaging (liver, spleen, adrenals, nodes)
- Management
- Mild: itraconazole
- Moderate to Severe: amphotericin induction followed by itraconazole
- CNS involvement: amphotericin for 4-6 weeks as induction
Blastomycosis¶
Background¶
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Endemic to Mississippi/Ohio river valley, southern and midwestern US, great lakes
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Pulmonary syndrome: cough, fever, hemoptysis, chest pain, dyspnea
- Can result in both an acute or chronic pneumonia, as well as ARDS
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Cutaneous: raised verrucous lesion, varying in color, with irregular borders
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MSK: osteolytic lesion, draining sinus, soft tissue swelling
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Multi-system: up to 20-40% of cases, most typically lung/skin involvement.
Evaluation¶
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Culture: typically takes 1-4 weeks
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Ag: urine >serum. ~90% sensitive, but only 80% specific because of cross-reactivity
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Serology: available, but not very useful because of high degree of cross-reactivity
Management¶
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Mild: PO itraconazole for 6-12 months with loading, check level at 2 weeks
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Moderate to Severe: induction with Amphotericin, followed by 6-12 months of PO itraconazole
Candida¶
Background¶
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Oropharyngeal: white plaques in mouth, change in taste, erythema without plaques
- Usually seen in infants, older adults, immunocompromised host (HIV or chemotherapy), inhaled steroid users
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Esophageal: odynophagia, especially retrosternal pain (AIDS defining illness)
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Vulvovaginitis: itching, burning, vaginal discharge, vulvar erythema, vulvar edema, dyspareunia, dysuria
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Balanitis: painful white plaques with burning and itching on the glans penis
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Mastitis: erythema, tenderness in breast feeding woman.
Management¶
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Depends on specifics, but typically nystatin or fluconazole EXCEPT C. glabrata (proof of fluconazole susceptibility needed) and C. krusei (intrinsically resistant to fluconazole)
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Cx generally not indicated unless complicated pt with extensive tx history for Candida
Additional Information¶
- Disseminated disease
- Presentation: Primarily immunocompromised populations (hematologic malignancies, solid organ transplant recipients, receiving chemotherapy, TPN, steroid use, broad spectrum antibiotics) and ICU settings (especially, burn, trauma, and neonatal)
- Diagnosis: Candida in a bacterial blood culture (NEVER contaminant)
- Start micafungin 100mg IV and consult ID for candidemia or if concerned for disseminated disease