07-Fungal II

Question 1

1. What is the most frequently reported cause of primary cutaneous aspergillosis?

Answer 1

1. M.c. cause of primary cutaneous aspergillosis is aspergillus flavus.

Question 2

2. The most common eumycotic organism in the US produces which color grains in its microcolony?

Answer 2

2. The most common cause of fungal (eumycotic) eumycetoma in the US is Pseudallescheria boydii. Produces white grains. Sexual state=Pseudallescheria boydii; Scedosporium apiospermum=asexual.

Question 3

3. Which fungus? Septate hyphae with 90° branching and thick walled barrel shaped retangular arthroconidia alternating with empty cells.

Answer 3

3. Septate hyphae with 90° branching and thick walled barrel shaped arthroconidia: coccidiodomycosis.

Question 4

4. What cutaneous manifestation is associated with a good prognosis in coccidiomycosis?

Answer 4

4. Erythema nodosum and erythema multiforme are associated with a good prognosis in coccidiomycosis and histoplasmosis.

Question 5

5. Which organisms in AIDS patients can produce molluscum-like lesions?

Answer 5

5. Can produce molluscum-like lesions in AIDS patients: CCHP Crypto, Coccidio, Histo, Penicillium.

Question 6

6. Name three dematiaceous fungi?

Answer 6

6. Alternaria sp., Bipolaris sp., Exophiala sp. Dematiaceous/phaeohyphomycosis.

Question 7

7. A blood culture from a neutropenic patient with onychomycosis most likely grew out which fungal organism?

Answer 7

7. Fusarium is one of the few molds, which yield positive blood cultures; Neutropenia is a risk factor.

Question 8

8. Name the three types of mycetoma?

Answer 8

8. Three types of mycetoma: eumycotic (true fungal), actinomycotic (filamentous organisms) and botryomycotic (bacterial infections).

Question 9

9. Which actinomycotic organism has red grains?

Answer 9

9. Actinomadura pelletieri- red.

Question 10

10. Nondermatophytes growing on Dermatophyte Test Media cause the media to turn what color?

Answer 10

10. Nondermatophytes cause the media to turn yellow due to acid by-products. Dermatophytes turn it red.

Question 11

11. A horticulturist of sphagnum moss topiaries comes in with a nodular eruption with lymphangitic spread and treatment with oral potassium iodide is initiated. What is the most well recognized side effect of this treatment?

Answer 11

11. Gastrointestinal distress. Beware Wolff-Chaikoff effect (hypothyroidism).

Question 12

12. Endemic to the Ohio, Missouri, Mississippi River Valleys where the bird and bat droppings in the soil contain this fungus?

Answer 12

12. Histoplasmosis. In parasitized macrophage differential.

Question 13

13. Diabetic patient complaining of a swollen tender right cheek. The PAS biopsy demonstrated ring forms and distorted wide hyphae with few septations and right angle branching. The diagnosis is?

Answer 13

13. Diabetes is a risk factor for Mucormycosis, ring forms in biopsy are the x-section of the wide sparsely septate hyphae.

Question 14

14. This organism is an algae, not a fungus. It stains with PAS and GMS and produces spherules in tissue. This organism is?

Answer 14

14. Prototheca wickerhami.

Question 15

15. A patient has a verrucous lesion of the nasal mucosa; the biopsy showed spherules ranging in size from 200 to 325 um. The mature endospores have a rough appearance. What is the diagnosis?

Answer 15

15. Rhinosporidiosis. Aquatic protozoan. Other organisms that produce spherules are Prototheca (8-20 um) and Coccidioides immitis (10-80 um).

Question 16

16. Penicillium marneffei is an infection endemic to which part of the world?

Answer 16

16. Penicillium marneffei is endemic to SE Asia. Bamboo rats may be reservoir.

Question 17

17. Medlar bodies are diagnostic of infection with which organism?

Answer 17

17. Chromomycosis. “copper pennies” or Medlar bodies. Seen with the dematiaceous fungi: Fonsecaea pedrosoi (most common, 90%), Fonsecaea compacta, Fonsecaea monophora, Phialophora verrucosa, Cladophialophora carrionii, Rhinocladiella aquaspera.

Question 18

18. The lymphocutaneous (regional lymphangitic) form of sporotrichosis is seen in which individuals?

Answer 18

18. Naive individuals who have never been exposed to fungus.

Question 19

19. Name five causes of the splendore-hoppli phenomenon.

Answer 19

19. Actinomycosis, Mycetoma, Sarcoid, Botromycosis, Sporotrichosis.

Question 20

20. What color are the grains for nocardia (asteroides), a cause of actinomycetoma/mycetoma?

Answer 20

20. White grains. Nocardia (asteroides) – white grains, Nocardia (brasiliensis) – white grains, Nocardia (caviae) – yellow-white grains.

Question 21

21. Cause of Keloidal Blastomycosis?

Answer 21

21. Locazia loboi. Lobomycosis. Affects humans and dolphins.

Question 22

22. DDX of parasitized marcrophages?

Answer 22

22. Histoplasmosis- H.capsulatum, Penicilliosis- P. marneffei, Granuloma inguinale- Calymmatobacterium granulomatis, Rhinoscleroma- Klebsiella rhinoscleromatis, Leishmaniasis- Leishmania spp.

Question 23

23. What is the most common site for dissemination in north American blastomycosis?

Answer 23

23. Skin is most common site for dissemination (80%). Chronic, slowly progressive, verrucous, granulomatous, thick crusts, and warty vegetations. Central involution with white scar formation. Broad based budding yeast.

Question 24

24. Cause of South American Blastomycosis?

Answer 24

24. Paracoccidioides brasiliensis. Remember the striking Mucocutaneous variant. Thick-walled organisms with multiple narrow-based buds may be seen (mariner’s wheel).

Question 25

25. 2nd only to candidiasis in opportunistic infection of patients with hematologic neoplasia. Vasculotropic/angiovasive. What is the organism?

Answer 25

25. Aspergillosis. 45° branching, septate hyphae.

Question 26

26. Name the three pathogenic molds that cause Mucormycosis?

Answer 26

26. Include: Rhizopus, Absidia , Mucor (“RAM”). Characterized by invasion of large blood vessels and nerves. Remember diabetic patients with rhinocerebral,

Question 27

27. AIDS patient who encountered pigeon droppings with molluscum contagiosum-like lesions. Organism?

Answer 27

27. Cryptococcosis. Cryptococcus neoformans. CNS and skin most common places to disseminate.

Question 28

28. Disseminated candidiasis in patient with leukemia. Most likely type of candida?

Answer 28

28. C. tropicalis.

Question 29

29. Most common cause of subcutaneous phaeohyphomycosis?

Answer 29

29. Exophiala jeanselmei.

Question 30

30. Most common cause of disseminated phaeohyphomycosis?

Answer 30

30. Bipolaris specifera.

Question 31

31. Opportunistic pathogen that is the most common fungus in burn patients?

Answer 31

31. Fusarium. Sickle-shaped, multiseptate macroconidia.

Question 32

32. Olecranon bursitis in otherwise healthy individuals caused by which organism (algae)?

Answer 32

32. Protothecosis (Prototheca wickerhamii or Prototheca zopfi). ganism (algae)?