Fungal and Immunocompromised Pneumonia Flashcards Preview

Pulmonary Week 2 > Fungal and Immunocompromised Pneumonia > Flashcards

Flashcards in Fungal and Immunocompromised Pneumonia Deck (72)
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1

What are the types of fungal infections?

-superficial and cutaneous mycoses
-subcutaneous (skin, lymphatics, subQ tissue)
-Endemic mycoses
-Oppoertunistic mycosis

2

What causes endemic mycoses?

dimorphic fungi

3

Notes about dimorphic fungi

-most common etiologic agents of pulmonary infection by fungi

-infection results from inhalation of spores that mold forms in soil

4

What does 'dimorphic' mean?

-grow as yeast in human tissue and as mold at room temp

5

What happens with spores of dimorphic fungi are inhaled?

they differentiate into yeasts or spherules. Most are self-limited but all can cause pneumonia and disseminate

6

What are some dimorphic fungi?

-Blastomyces dermatitidis
-Histoplasma capsulatum
-Coccidioides immitis
-Paracoccidioides brasiliensis

7

Where is Histoplasma capsulatum endemic?

Mississippi and Ohio River

8

Where does Histoplasma capsulatum grow?

soil and bird droppings

9

How does Histoplasma capsulatum infection present?

-mostly asymptomatic pulmonary infection
-but can have fever, chills, cough, chest pain

10

In AIDS, Histoplasma capsulatum can disseminate. What organs are typically affected?

-BM (pancytopenia)
-Mouth/Gi (ulcers)
-Skin (rash, nodules)

11

Tissue biopsy of positive Histoplasma capsulatum will show what?

oval yeast cells within macrophages

12

How else can Histoplasma capsulatum be diagnosed?

-serology
-Urinary antigen (good for AIDS patients)

13

How does Histoplasma capsulatum show on CXR?

-infiltrates
-mediastinal LAD
-cavitary lesions

14

What are two possible skin manifestations of Histoplasma capsulatum infection?

-skin rashes
-erythema nodosum

15

Note about skin rashes in Histoplasma capsulatum

seen in disseminated Histo (rash is rare, but common in AIDS/immunocompromised)

16

What is erythema nodosum?

tender nodules that present on extensor surfaces (tibia and ulna skin). Result from delayed hypersensitivity response to fungal antigen and is an indicatory of poor prognosis (not specific to histo but also seen in coccidioides and TB)

Aka desert bumps

17

Where is Blastomyces dermatitidis endemic?

Ohio/Mississippi River Valley, Missouri, and Arkansas River basins (grows in moist soil)

18

How does Blastomyces dermatitidis present?

asymptomatic respiratory illness, 50% will have cough, chest pain, sputum, fever/night sweats

most resolve spontaneously

19

Disseminated Blastomyces dermatitidis results in what?

ulcerated granulomatous lesions of the skin (70%), bone (33%), GI tract (25%), and CNS (10%). Seen in both immunocompetent and compromised patients

20

What does tissue biopsy of Blastomyces dermatitidis show?

thick-walled yeast cells with **single broad-based bud**

21

How is Blastomyces dermatitidis diagnosed?

-CXR (lobar consolidation)
-tissue biopsy
-serology

22

How is Histoplasma capsulate treated?

Ampho B for severe and Itra otherwise

23

How is Blastomyces dermatitidis treated?

Ampho B for severe and Itra otherwise

24

Where is Coccidioides immitis endemic?

Southwest and Latin America

25

Describe the pathogenesis of Coccidioides immitis

In the lungs, large spherules form and filled with endospores. Upon rupture, endospores are released and differentiate into new spherules

26

How does Coccidioides immitis present?

-mild flu-like illness with fever and cough ('valley fever') in 10%
-erythema nodosum

27

How common is dissemination in Coccidioides immitis?

1% (to bone, meninges, and skin)

28

What ethnicities are at increased risk for dissemination of Coccidioides immitis?

-AA, Filipinos, and women in 3rd trimester

29

____ is common with Coccidioides immitis

Eosinophilia

30

How is Coccidioides immitis treated?

-Ampho for persistent lung lesions or disseminated

-Fluconazole for meningitis