4-Fungal Infections Respir Tract

Question 1

zygomycoses/mucormycosis

Answer 1

from zygomycetes family- dz/infection uncommon but fatal
-molds common found @ foods, vegetation, soil

risk factors: immunosup, diabetes, burns, neonates

Question 2

zygomycetes fungi

Answer 2

1. rhizopus
2. absidia
3. mucor

non septate hyphae + sporangia with sporangiospores

Question 3

rhinocereberal zygomycosis

Answer 3

primarily in diabetic pts

og @ sinuses when inhale spores > extends to neighboring tissues (nose, hard palate, eye, brain)

nasal congestion + blood tinged rhinorrhea + tender sinuses + headache + fever > facial/periorbital edema > mental status, coma, death

Question 4

dx zygomycoses

Answer 4

observe hyphal elements in clinical material/samples
-broad aseptate hyphae with branching at right angles @ blood vessels

treat with amphotericin B

Question 5

candidiasis

Answer 5

C. albicans
-normal flora as yeast form @ skin, mucus membranes, GI tract
-exist in hyphal form @ tissue, pathologic

Question 6

thrush presentation

oral candidiasis

Answer 6

common infants, AIDS, adults on steroids, antibiotics, antineoplastic drugs

diffuse erythema + white patches/plaques on buccal mucosa, throat, tongue, gums
-lesions are combo of yeast and pseudohyphal forms C. albicans

Question 7

thrush dx

Answer 7

direct observation
-not need culture, do germ tube test

treat oral formulations of nystatin or azoles as mouth wash or lozenges

Question 8

systemic mycoses

Answer 8

acquired by inhalation of fungi from environment as hyphae or spores
-non opportunistic so can cause dz in healthy indivs

all start with pulmonary infection

Question 9

fungi systemic mycoses

Answer 9

1. coccidioides immitis-dimorphic
2. paracoccidioides brasiliensis-dimorphic
3. blasomyces dermatitidis-dimorphic
4. hisoplasma capsulatum

hyphae to yeast in tissues

Question 10

histoplasmosis

Answer 10

@mississipii and ohio river valleys

from histoplasma capsulatum in soil under humid climate conditions (bird and bat droppings)
-micro or macro conidia inhalation with round bump appearance

aka darlings/cave dwellers/ spelunkers dz

Question 11

histoplasmosis clinical

Answer 11

usually asymptomatic but may be hospitalized
-macrophages will phagocytose yeast forms so will resolve without intervention unless replicate within macro

mild flu like symps, dry cough, fever, fatigue
-calcification of pulmonary lesions, chest pain

Question 12

chronic pulmonary/disseminated histoplasmosis

Answer 12

in immunocomp people so acute/fatal OR chronic/debilitating
-fever, night sweats, anorexia, weight loss, fatigue + respir symps
-hepatosplenomegaly + lymphadenopathy if spread

simialr to TB

Question 13

histoplasmosis dx

Answer 13

direct observ in tissues as yeast form
-antigen detection in urine

amphotericin B or itraconazole + suppressive therapy for AIDS pts to prevent relapse

Question 14

blastomycosis

Answer 14

exist in moist soil high in decaying vegetation content @ohio, miss river valley + missouri, ark river basins

aka gilchrist, chicago’s, north american blastomycosis

dimorphic fungus- yeast have really thick cell walls and thick bud base, large size
-disting from H capsulatum

also infect dogs and horses

Question 15

blastomycosis clinical

Answer 15

primary pulmonary dz + ulcerative lesions @ skin, bone, urogenitial tract

acute cough, fever, chills. flu like > chronic night sweat, weight loss, sputum production > disseminated bone necrosis, granuloma formation, prostate infection
-most asymp tho

Question 16

blastomycosis dx

Answer 16

observe distinct yeast forms
-antigen testing urine

treat with amphotericin B for disseminated or immunosup OR azoles if uncomplicated pulmonary

Question 17

paracoccidioidomycosis

PCM

Answer 17

@south and central america
-paracoccidioides brasiliensis dimorphic

men (bc estrogen may inhibit)

Question 18

PCM clinical

Answer 18

most asymptomatic > chronic cutaneous and mucocutaneous ulcers

yeast form has multi buds ‘ship wheel’ or ‘mickey mouse ears’

Question 19

coccidioidomycosis

Answer 19

highly endemic @ san joaquin valley cali and southern arizona aka drought rain drought pattern
-arthroconidia (brittle hyphae) blows around in dust

aka valley fever

Question 20

coccidioidomycosis clinal

Answer 20

C. immitis or C. posadasii
-when arthocondida inhaled converts to spherule (multinuc structure)

some asymp but some moderate influenza like > disseminate rarely with infection in bones, joints, skin, CNS

Question 21

coccidioidomycosis dx

Answer 21

direct obs spherules, antigen
will resolve spont in a few weeks

Question 22

coccidial meningitis

Answer 22

subtype of coccidioidomycosis
devs slowing with inc headaches, fever, stiff neck, neuro signs
-frequently fatal if untreat

Question 23

cryptococcosis

Answer 23

leading form of fungal meningitis

from C. neoformans/ C. gatti in abundant soil contam with bird/pigeon droppings

Question 24

cryptococcosis clinical

Answer 24

asymp or mild spont resolving flu like
>meningitis: intermittent bouts of headaches, irritability, dizziness, other CNS
>disseminated = skin and bone lesions

esp AIDS or immunosup pts

Question 25

cryptococcus dx

Answer 25

india ink stain from spinal fluid, skin lesions, sputum

treat meningitis with long term combo of amphotericin B + 5 fluorcytosine or fluconazole, suppressive therapy if AIDS

Question 26

pneumocystis jirovecii/carinii pneumonia

PCP

Answer 26

highly lethal form of pneumonia
-almost exclusively in AIDS pts

not totally fungi just closely related, similar processes to protozoa
pneumocystis carinii.jirovecii

Question 27

PCP clinical

Answer 27

inhale cysts

dyspnea, nonprod cough, fever > interstitial pneumonitis with cellular infiltrate, cyanosis, tachypnea > death from asphyxiation

Question 28

PCP dx

Answer 28

id organisms (trophozoite, sporozoites, cysts) from biopsy, aspiration, bronchial washing
-special stain for carbs

treat trimethoprim-sulfamethoxazole to interfere with folate syn + prophylaxis and suppressive therapy for AIDS

Question 29

aspergillosis

Answer 29

aspergillus rarely pathogenic in normal immune status
-unless immuno comp

**A. fumigtus and flavus **
-true mold, septae

Question 30

acute pulmonary infection

aspergillomas

Answer 30

aka fungus balls
-colonize pre existing lung lesions, unilateral
-usually asymp unless see on xray

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Question 31

aspergillosis dx

Answer 31

hyphal elements in sputum (hyphae within matrix of fibrin and cellular debris)
-v shaped branching at 45 degrees esp in blood vessles

treat with azoles, echinocandin, amphotericin B, surgery