Systemic Mycoses 1

Question 1

Endemic mycoses share some features. These are? (6, review more than memorize)

Answer 1

• In nature
• In a geographic region
• Inhale->lungs->dissemination
• human-human transmission almost never occurs
• often asymptomatic
• healthy CAN be infected

Question 2

A bronchoscopic biopsy grows mold 5 days after visiting California central valley. I’ve got fever, chest pain, cough, night sweats. What do I have?

Answer 2

Coccidioidomycosis

Question 3

Doc, what will happen to me now that I’ve got coccidioidomycosis? (3)

Answer 3

• asymptomatic (60%)
• valley fever that goes away on its own (30%)
• progressive lung nodules or dissemination

Question 4

How is coccidioidomycosis diagnosed? (4)

Answer 4

• spherules on wet prep
• BIOHAZARD for lab (like all dimorphics)
• IgM or IgG in serum are useful for those NOT in endemic areas
• hyphae w/ alternating barrel-shaped arthroconidia

Question 5

coccidioidomycosis treatment?

Answer 5

usually not needed

Question 6

A chimney sweep or a bat cave explorer comes to you w/ pneumonia symptoms. What is it?

Answer 6

histoplasmosis

Question 7

Histoplasmosis pathogenesis?

Answer 7

inhale microconidia/spores ->budding yeasts in body -> get yeasts in macrophages (or disseminates by bloodstream)

Question 8

Histoplasmosis symptoms?

Answer 8

• 95% asymptomatic
• Lung: either self-limited, or chronic cavitary fibrosing mediastinitis
• Systemic: sepsis in immunocompromised

Question 9

Histoplasmosis diagnosis?

Answer 9

• BIOHAZARD dimorphic: Giemsa stain & see yeast both extracellular and inside macrophages. (look like acorns)
• Urine antigen test BEST

Question 10

African histoplasmosis is caused by what organism?

Answer 10

histoplasma capsulatum var. duboisii

Question 11

How is African histoplasmosis different than normal histoplasmosis?

Answer 11

• Larger, thick-walled yeast
• Get giant cells
• Less pulmonary involvement, but more bone/skin problems.

Question 12

Histoplasmosis treatment?

Answer 12

Usually none. For severe: amphotericin B

Question 13

Wisconsin! (or EAST U.S.) Lung, skin, & bone lesions, what fungus?

Answer 13

Blastomycosis

[broad based budding!]

Question 14

Blastomycosis is asymptomatic in what %?

Answer 14

1/2 (so high virulence for a fungus) (it can turn chronic in some!)

Question 15

Blastomycosis diagnosis involves what?

Answer 15

• BIOHAZARD dimorphic. Wet prep, culture (which takes 4 wks!), or ELISA for exoantigen A.
• Broad-Based Budding & lollipops coming off the hyphae!

Question 16

Blastomycosis treatment?

Answer 16

-Amphotericin B (or others, the point is you actually DO treat this fungus)

Question 17

I’ve got fever, cough, nodular lung lesions, painful ulcerated oro-labial lesion. Rarely my disease disseminates. I just came from Guatemala. What do I have?

Answer 17

Paracoccidioidomycosis “South American Blasto”

Question 18

I look like a pilot’s wheel on wet prep. What am I? Should I be treated?

Answer 18

• paracoccidioidomycosis.

- Yes

Question 19

I’ve got a rash on face, lymphadenopathy, palpable spleen tip, bilateral chest x-ray infiltrate. HIV positive, and I came from Vietnam. What do I have?

Answer 19

Penicillium marneffei

[think HIV in SouthEast Asia! Soil and bamboo rats.]

Question 20

What does Penicillium marneffei look like on stain?

Answer 20

elliptical yeast form w/ fission septae. red. (dimorphic beware!!)

Question 21

Penicillium marneffei treatment?

Answer 21

amphotericin B

Question 22

I rolled in pigeon poo. I’ve got pulmonary problems, MENINGITIS, fatigue, somnolence, HIV, mental status changes, and you see encapsulated yeast on india ink prep as well as a positive polysaccharide antigen test in CSF (BEST test) as well as mucoid yeast colonies that grew on GMS stain. What do I have?

Answer 22

Cryptococcus neoformans (C. gatii if the pigeon lived in a eucalyptus tree)
[think meningitis in HIV patient! It it's NOT an HIV patient, it's C. gatii)

Question 23

What antibiotic is used for life for prophylaxis of some fungi for immunocompromised?

Answer 23

fluconazole

Question 24

What antibiotic is used for really bad fungal infections?

Answer 24

amphotericin B