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23 Cards in this Set
- Front
- Back
Compare and contrast the diagnosis of fungal infections at cutaneous and mucosal sit risky vs.systemic
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cutaneous/ mucosal- accesible tissues, easy but under-utilized
systemic- early Dx is difficult |
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Why is early Dx of fungal infections more difficult with systemic infections vs. cutaneous
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systemic infections:
-lack of inflammatory response in host -invasive Dx procedures -lack of sensitive, minimally invasive assays |
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Describe the Dx procedure for vulvovaginal candidiasis and why it is important
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-important to carry out Dx because less than 50% of sxs were actually VVC
-Take swab, ph 4-4.5 wet mount 10% KOH and culture |
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T/F blood cultures are a reliable means for Dx of ICI
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false, Dx for invasive candidiasis is only 50-70% acccurate
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List 5 non culture Dx methods for candidiasis
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1. serum ab (cell wall mannan)
2. serum ag (cell wall mannan) 3. metabolites (mannose, enolase, arabinitol, secreted aspartyl proteinase) 4. B 1,3 glucan assay 5. PCR (18s ribosomal) |
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Culture of Candida from the urine w/ or w/o pyuria does not imply clinical significance. What situations suggest a significant infection
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-persistence after catheter removal
-confirmation with 2nd urine sample |
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When should urinary candidasis be treated
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-symptomatic
-asymptomatic if obstructive uropathy, impending urological procedure, syndrome of disseminated candidiasis |
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In addition to the blood, where might candida be found in infections
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peritoneum, drains, urine, sputum, skin/ wounds
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List 4 ways to differentiate Candida species in the lab
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1. azole antibiotic species activity
2. germ tube test 3. sugar assimilation 4. 26s rRNA (PNA FISH) |
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T/F an "ugly" nail is diagnostic of a fungal infeciton of the nail (onychomcosis)
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false, only 50% of ugly nails are caused by fungal infection
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Describe the procedure used to Dx a fungal nail infection
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clip or scrape the skin, soak in KOH and wet mount
-culture -PAS histopathology |
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List 4 ways that aspergillus can present as disase
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1. colonization of lungs, sinuses
2. allergic ABPA, AFS 3. saprophytic/ asgergilloma in pre-existing lung cavity 4. invasive pulmonary, disseminated |
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Describe how aspergillus can be Dx'ed with histology and microscopy
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-Gomori methenamine silver stain for detecting hyphae
-dichotomous branching, septate, nonpigmented |
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What features of a chest radiograph may suggest invasive aspergillosis
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-patchy peripheral infiltrates progressing to dens consolidation
-solitary or multiple nodules progressing to cavitated nodules -wedge shaped pleural based lesions |
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What features of a CT scan may indicated invasive aspergillosis
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-earlier and better assessment than radiography
-Halo sign= early manifestation, rim of ground glass attenuation surrounding nodule, corresponds to rim of hemorrhage surrounding pulmonary infarction |
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T/F you should be suspicious of cultures for histoplasmosis because positive results could be from environmental contamination
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false. While this is a problem for aspergillous, Hc is never a contaminant
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List some common sites/ manifestations of Hc
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acute pumonary, disseminated, percarditis, meningitis, joints/bones
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list some common sites/ manifestations of blastomycosis
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pulmonary> skin> bone> brain, other
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How might blastomycosis be diagnosed
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traditional smear and culture- big broad based buds
urine antigen (galactomannan) |
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List some common sites/ manifestations of coccidioidomycosis
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60% are asymptomatic/ self limited
pulmonary> CNS, bone, skin |
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List three ways to Dx coccidioidomycosis
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1. antibodies
2. tube precipitin 3. complement fixation |
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How might cryptococcosis be Dx'ed
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CSF smear with India ink looking for zone of exclusion => capsule
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Where is a good place to look for histoplamosis antigen in disseminated disease
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urine
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