Systemic Mycoses Flashcards
List of systemic mycoses
Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi
Morphology of systemic mycoses
Histoplasma, Blastomyces, Paracoccidiodes, Penicillum marneffi are dimorphic: “mold in the cold, yeast in the heat”
1 exception is Coccidioides: “mold in the cold, spherule in heat”
Yeast forms have unique morphologies!
Transmission of systemic mycoses
For Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi
Respiratory
No person-person
Clinical presentation of systemic mycoses
For Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi
- Mostly asymptomatic unless immunocompromised. Need high infectivity dose to cause disease in immunocompetent person.
- All can cause Pneumonia and disseminate (Extrapulmonary Manifestation)
- can have latent period and reactivation disease.
Treatment of systemic mycoses
For Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi
Azole for local infection
Amphotericin B for systemic infection
Histoplasma Capsulatum epidemiology
Inhaled microconidia (spores) from: spelunking, construction work, bat guano (high concentrations), Ohio and Mississippi River Valleys and other countries (Caribbean)
Histoplasma Capsulatum morphology
Dimorphic (mold/yeast), Intracellular (monocytes/macrophages ). In culture see it growing inside of macrophages. Smaller then RBC.
Histoplasma Capsulatum Clinical presentation
Dissemination/sepsis /reactivation in immunocompromised/defects in CMI with high mortality (>80%);
PULMONARY (can look like miliary TB, or regular TB with granulomas), cardiac, rheumatic conditions; can be asymptomatic
Histoplasma Capsulatum diagnosis
Most Important: Urine antigen test.
The possible other options: Visualization on sputum with silver stain, peripheral blood smear, bone marrow biopsy, Broncheoalveolar lavage; skin/liver/LN bx poor yield
Treatment of histoplasma capsulatum
Amphotericin B, Itraconazole, Voriconazole
Blastomyces Dermatitidis morphology
Dimorphic, saprophytic mold in soil (25C); Broad Based Budding yeast
“Blasto = Broad-Based Buds”
Same size as RBC.
Clinical presentation Blastomyces Dermatitidis
Pulmonary (chronic pneumonia); cutaneous lesions (papules, nodules, microabscesses – looks like mold) and bone lesions from hematogenous spread
ExtraPulm - “BLaST = Bones, Lungs, and Skin, (TB presentation)”
Diagnosis of Blastomyces Dermatitidis
Broad-based budding of yeast; silver stain
Epidemiology of Blastomyces Dermatitidis
Inhalation of spores (rarely cutaneous), environmental (soil, decaying wood, river banks);
geographic overlap with Histo: Great lakes and Ohio River valleys
Treatment of Blastomyces Dermatitidis
Amphotericin B, itraconazole, fluconazole
Coccidioides Immitis morphology
Dimorphic: multinucleate spherule and
mold (barrel-shaped arthroconidia is infectious unit).
Spherule filled with endospores in body, not yeast. Larger then RBC.
Coccidioides Immitis clinical presentation
Asymptomatic (many), flu-like symptoms (10-16 days post-exposure);
San Joaquin Valley Fever in 5% (rash, erythema nodosum (desert bumps), erythema multiforme, joint pain, conjunctivitis);
may disseminate MENINGITIS
Diagnosis of Coccidioides Immitis
LARGE spherule in culture, PPD-like skin test (type IV hypersensitivity)
Epidemiology of coccidioides Immitis
Soil in SW US, Latin America; disturbed soil (inhaled spores, which becomes LARGE spherule) –>Military, Archaeologists, Construction workers. Increased rate after earthquakes
“Cocc your gun in the South and knock over a Barrel of spores”
genetic high risk groups: Filipino>African-American>Native Americans
Treatment of coccidioides immitis
Amphotericin B (+ fluconazole if immunocompromised)
paracoccidioides brasiliensis morphology
Dimorphic, Mariner’s Wheel (multiples buds w/ narrow stalks)
“Paracoccidio parasails with the Captain’s Wheel all the way to Latin America”
Paracoccidioides brasiliensis clinical presentation
Lungs –> dissemination; LONG latency (can be > 10 yrs); PULMONARY (necrotizing granulomas, dry cough), lymphadenopathy, sometimes cutaneous fistulae; CXR shows patchy nodular densities and sometimes consolidations; can be asymptomatic
Paracoccidioides brasiliensis diagnosis
Culture of biopsy or bronchoalveolar lavage budding yeast with Mariner’s (captain’s) wheel appearance
Paracoccidioides brasiliensis epidemiology
Latin America (Mexico to Argentina; highest in Brazil); 15:1 male predominance (estrogen may be protective); inhaled spores “Paracoccidio parasails with the Captain’s Wheel all the way to Latin America”
Paracoccidioides brasiliensis treatment
Itraconazole OR TMP-SMX, Amphotericin B if severe
Penicillum Marneffi morphology
Dimorphic Yeast and mold
Clinical presentation of penicillum marneffi
Pulmonary, dissemination, fever, weight loss, pancytopenia, HEPATOMEGALY, umbilicated skin lesions (cutaneous disseminated disease)
Diagnosis of penicillum Marneffi
Binary Fission in yeast phase
Epidemiology of penicillum marneffi
Endemic to tropical Asia; bamboo rat (zoonotic reservoir); immunocompromised
*3rd most common opportunistic infections in endemic area (after TB and Crypto) in AIDS patients in N. Thailand
What can cause disseminated skin lesions?
Causes umbilicated skin lesions
disseminated cryptococcosis or disseminated histoplasmosis or disseminated penicillumosis
Treatment of penicillum marneffi
Amphotericin B and 5-Fluorocytosine
