Pulmonary Fungal Infections 1 Flashcards
Coccidioidies is thermally dimorphic, what are the two forms it takes? And in what environment does it take these forms?
Mold in soil: hyphae with alternating arthrospores and empty cells
Spherule in lung tissue
Where is coccidioides endemic?
US SW, latin america
In wet weather wha does coccidioides do? dry?
grows in wet, releases infectious arthrospores in dry
How is coccidioides transmitted?
Inhaled arthrospores, NOT P2P
How does coccidioides present?
60% asymptomatic/ flu-like: clearance by innate or containment by CMI
Moderate: valley fever/ desert rheumatism: pulm. + Erythema nodosum
severe: major pneumonia or dissemination (bare or hidden in macrophages)
What factors put you at risk for coccidioides?
age, race, preg, immunocompromise, occupational exposure
How do you diagnose coccidioides?
exam, hx, PPD, biopsy spherules, culture (look for dimorphism), serology in dissemination
How do you treat coccidioides?
mild: NA
persistent lung lesions/ dissemination: Amphotericin B
meningitis: oral azoles long-term, may add intrathecal amphotericin B
Pregnant: amphotericin B
what form does histoplasma take?
THERMALLY DIMORPHIC: mold, yeast
Where is histoplasma endemic?
Ohio, Missouri, Mississippi river valley
How is histoplasma transmitted?
spores are inhaled
How does histoplasma present in previously-healthy?
Pulm sx, granulomas, high does exposure may mimic TB
How does histoplasma present in CMI-deficient host?
it disseminates in macrophages, look for pancytopenia and ulcerations on tongue
What are immunosuppressed patients exposed to blastomyces at risk for?
hematogenous spread
How does blastomyces present?
Moderate acute: pneumonia + purulent sputum
Moderate chronic: Mimics TB
Severe acute: ARDS
What skin sx may be present in blastomyces infection?
erythema nodosum, ulcerating skin lesions
How do you diagnose blastomycosis?
sputum microscopy–> yeast
culture–> hyphae with pear-shaped conidia
biopsy–> yeast with suppurating (NONCASEATING) GRANULOMAS
how do you treat blastomyces?
itraconazole, amphotericin B if severe, combine with healthier lifestyle (semi-opportunistic)
Where is paracoccidioides endemic?
rural latin america
Who is at risk for severe paracoccidioides infection?
children and immunocompromised
men in agriculture or construction who have large exposure are also at risk for moderate infection
Transmission of paracoccidioides
inhalation of conidia which grows in wet soil
tx for paracoccidioides
itraconazole, Amphotericin B if severe, semi-opportunistic so combine with healthier lifestyle
What aspects of the history are important to dx histoplasma?
exposure to birds, bats, endemic area travel, immunocompromised, occupation
What tests should performed to diagnose histoplasma?
biopsy: yeast in macrophages
cultures: dimorphism
ELISA: histoplasma polysaccharide antigen
