Systemic Mycoses

Question 1

List of systemic mycoses

Answer 1

Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi

Question 2

Morphology of systemic mycoses

Answer 2

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!

Question 3

Transmission of systemic mycoses

Answer 3

For Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi
Respiratory
No person-person

Question 4

Clinical presentation of systemic mycoses

Answer 4

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.

Question 5

Treatment of systemic mycoses

Answer 5

For Histoplasma, Coccidioides, Blastomyces, Paracoccidiodes, Penicillum marneffi
Azole for local infection
Amphotericin B for systemic infection

Question 6

Histoplasma Capsulatum epidemiology

Answer 6

Inhaled microconidia (spores) from: spelunking, construction work, bat guano (high concentrations), 
Ohio and Mississippi River Valleys and other countries (Caribbean)

Question 7

Histoplasma Capsulatum morphology

Answer 7

Dimorphic (mold/yeast), Intracellular (monocytes/macrophages ). In culture see it growing inside of macrophages. Smaller then RBC.

Question 8

Histoplasma Capsulatum Clinical presentation

Answer 8

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

Question 9

Histoplasma Capsulatum diagnosis

Answer 9

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

Question 10

Treatment of histoplasma capsulatum

Answer 10

Amphotericin B, Itraconazole, Voriconazole

Question 11

Blastomyces Dermatitidis morphology

Answer 11

Dimorphic, saprophytic mold in soil (25C); Broad Based Budding yeast
“Blasto = Broad-Based Buds”
Same size as RBC.

Question 12

Clinical presentation Blastomyces Dermatitidis

Answer 12

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)”

Question 13

Diagnosis of Blastomyces Dermatitidis

Answer 13

Broad-based budding of yeast; silver stain

Question 14

Epidemiology of Blastomyces Dermatitidis

Answer 14

Inhalation of spores (rarely cutaneous), environmental (soil, decaying wood, river banks);
geographic overlap with Histo: Great lakes and Ohio River valleys

Question 15

Treatment of Blastomyces Dermatitidis

Answer 15

Amphotericin B, itraconazole, fluconazole

Question 16

Coccidioides Immitis morphology

Answer 16

Dimorphic: multinucleate spherule and
mold (barrel-shaped arthroconidia is infectious unit).
Spherule filled with endospores in body, not yeast. Larger then RBC.

Question 17

Coccidioides Immitis clinical presentation

Answer 17

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

Question 18

Diagnosis of Coccidioides Immitis

Answer 18

LARGE spherule in culture, PPD-like skin test (type IV hypersensitivity)

Question 19

Epidemiology of coccidioides Immitis

Answer 19

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

Question 20

Treatment of coccidioides immitis

Answer 20

Amphotericin B (+ fluconazole if immunocompromised)

Question 21

paracoccidioides brasiliensis morphology

Answer 21

Dimorphic, Mariner’s Wheel (multiples buds w/ narrow stalks)

“Paracoccidio parasails with the Captain’s Wheel all the way to Latin America”

Question 22

Paracoccidioides brasiliensis clinical presentation

Answer 22

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

Question 23

Paracoccidioides brasiliensis diagnosis

Answer 23

Culture of biopsy or bronchoalveolar lavage  budding yeast with Mariner’s (captain’s) wheel appearance

Question 24

Paracoccidioides brasiliensis epidemiology

Answer 24

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”

Question 25

Paracoccidioides brasiliensis treatment

Answer 25

Itraconazole OR TMP-SMX, Amphotericin B if severe

Question 26

Penicillum Marneffi morphology

Answer 26

Dimorphic Yeast and mold

Question 27

Clinical presentation of penicillum marneffi

Answer 27

Pulmonary, dissemination, fever, weight loss, pancytopenia, HEPATOMEGALY, umbilicated skin lesions (cutaneous disseminated disease)

Question 28

Diagnosis of penicillum Marneffi

Answer 28

Binary Fission in yeast phase

Question 29

Epidemiology of penicillum marneffi

Answer 29

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

Question 30

What can cause disseminated skin lesions?

Answer 30

Causes umbilicated skin lesions

disseminated cryptococcosis or disseminated histoplasmosis or disseminated penicillumosis

Question 31

Treatment of penicillum marneffi

Answer 31

Amphotericin B and 5-Fluorocytosine