DIT Mycology Flashcards
Classic scenario of pancreatic cancer in head of pancreas?
50 year old man with painless jaundice
Presentation of candidal esophagitis?
AIDS, leukemia, lyphoma
Painful swallowing with substernal chest pain and feeling of obstruction when swallowing
Describe vulvovaginitis with candida
diabtic or after antibiotic
Severe itching, edema, discharge
ACIDIC pH
Disseminated candidiasis can attack patients where?
Anywhere! it spreads and is dangerous. Endocarditis in IV drug users is possible but can really hit anything
Dx and tx of candidiasis?
Blood culture: cells have germ tubes (also pseudohyphae)
Derm: topical azole or fluconazole
Oral: nystatin or fluconazole
Systemic: fluconazole if immune system works, amphotericin B if immunocompromised
What is attacked by cryptococcus? Where is it from?
Cryptococcus is meningitis in AIDs patients
Found in pigeon shit and soil
Cryptococcal diagnosis (buzzword city)
Soap bubble imaging in brain
Latex agglutination (b/c capsule)
muCiCaramine (CryptoCoCCus)
India Ink
Tx cryptococcal meningitis?
Amphotericin B and flucytosine followed by fluconazole
Stain for PCP?
Imaging?
Silver stain
Ground glass appearance of interstitial infiltrates
Tx for PCP if sulfa allergy?
Pentamidine and clindamycine + primaquine (dapsone for prophylaxis if sulfa allergy)
Aspergillus can cause what?
Allergic bronchopulmonary with asthma or CF
Aspergillomas in lung cavities
Aflatoxin for hepatoccelular carcionma
Invasive in immunocompromised or CHRONIC granulomatous disease
Dx of aspergillus? know!
A for Acute Angles in Aspergillus. not dimorphic
Who is affected by Mucor and Rhizopus?
Dx?
ketoacidotic diabetic and leukemic patients
Penetrate cribriform plate into brain
Wide angles (like 90 degrees) think upside down M in mucor for W in Wide angles
Presentation of mucor?
Tx
Rhinocerebral. Facial pain and headache with large necrotic lesions (black escar)
CN deficits and blindness
Dx: tissue biopsy
Tx: debridement and amphotericin B
What are the three primary causes of pruritic skin fungus?
Dx:
skin MET skin and spread it
Microsporum
Trichophyton
Epidermophyton
Mold hyphae in KOH prep
they can cause ringworm and onychomycosis
Hypopigmented spots on shoulders andstuff (think on kids at pools) are caused by what?
Tx?
Tinea versicolor (changes skin COLOR). Malassezia furfur
Degrades lipids and stuff and makes skin hyper or hypo pigmented
Azoles or topical selenium sulfide
What looks like spaghetti and meatball on KOH prep?
Tinea versicolor (malasssezia furfur). The hyperpigmented spots
Opportunistic fungal infections?
Candidiasis
Aspergillus
Cryptococcus
Mucor and Rhizopus
3 question warmup. Organism with following statements? (not fungus)
Cat scratch Cat bite Cat shit Puppy shit Animal urine
Cat scratch: bartonella Cat bite: pastuerella m Cat shit: toxoplasma Puppy shit: yersinia enter.. Animal piss: leptospira or hantavirus if mouse pee
Localized mycoses tx?
Severe or disseminated or complicated infection tx?
Azoles for most localized or uncomplicated
Amphotericin B for severe
Granulomas seen with mycoses?
Non-caseating granulomas (one way to differentiate from TB)
What diseases are associated with birds?
HIsto Cryptococcus (pigeon) Chlamydophila psititaci H5N1 West Nile
Patient was spelunking and has pulmonary infection. Disease? What does it look like? What region do you find it?
Histo is in bat dropping (So encountered bat shit)
Also in bird shit
Histoplasmosis HIDES in macrophages
Mississippi and Ohio River valleys
Fungi if it is cold (dimorphic)
Blasto affects what? What does it look like?
Enters by pulm route and is pulm infection, can disseminate to involve skin and bone
Broad Based Budding (it is same size as RBC)
dimorphic, btw so fungus if cold)
Where is blasto geographically?
Mississippi valley from central america to canada
What does coccidio look like? Where is it geographically?
Coccidio Crowds (spherules is where they divide and they get huge with a bunch of daughter cells until they burst)
SW united states. San Joaquin Valley fever
from spores in dust and gets thrown into air with earthquake (and sandstorms)
Coccidio symptoms?
usually asymptomatic or mild
Can be severe pneumo
Can disseminate to CNS bone and skin (skin most common dissemination)
What does paracoccidiomycosis look like? Where is it geographically?
What symptoms can it cause?
Paracoccidiomycosis PARAsails with CAPTAINs week all the way to Latin America
Captain wheel
Severe pneumonia
What is sporothrix associated with? what does it look like?
Symptoms?
Dimorphic fungus that looks like a cigar yeast
Traumatic from rose thorn or sphagnum moss
You get a local pustule or ulcer and can follow lymphatics but very little systemic illness
They are painless
Tx of sporothrix? mnemonic
ITraconazole or potassium iodid
plant a ROSE in a POTassium iodide
Amphotericin B mechanism?
tox? (one is super important to know and how to limit it)
amphoTEARS holes in membrane
Binds ergosterol in cell membrane to make pores that leak
Binds cholesterol in human cells too a bit… oops.
TamphoTERRIble for kidneys. Must hydrate, fever chills, hypotension, phlebitis and arrhythmia
Nystatin mechanism? Use?
Tox
Binds ergosterol (like amphotericin) but too toxic to be used systemically
Super toxic so only topical. Not bad if not injected. Not absorbed orally
Topical things. Swish and swallow for oral candidiasis (not absorbed so its safe
Azoles mechanism?
inhibit ergosterol synth by blocking P450
Fluconazole use?
Crosses BBB.
Cryptococcal meningitis prophylaxis in AIDs
Also candidal
Side effects of azoles?
Block cyp450 (so hepatotoxicity AND… less testosterone production: Gynecomastia)
Elevated liver enzymes
Mechanism of flucytosine?
Use?
Tox?
FLUcytosine converted to 5-FLUorouracil (disrupts DNA and RNA synthesis)
Used in combo with ampho B for systemic candida and cryptococcus
Bone marrow suppression makes sense
What are the echinocandins?
Mechanism?
Use
Tox?
-fungin (that is what they kill, fungus) [cASPofungin]
Inhibit cell wall by inhibiting synth of Beta glucan
cASPofungin for invasive ASPergillosis
Toxicity: GI upset and histamine release (flushing)
Terbinafine mechanism?
Use?
Tox?
Inhibits squalene epoxidase so can’t make ergosterol
Use: tinea pedis and corporis
If taken orally: it is deposited in skin and nails, right where you want it
Tox: HEPATOTOXIC (David told me!) and GI symptoms
Griseofulvin mechanism?
Why it is useful?
Tox?
Interferes with microtubule function. Disrupts mitosis.
Good b/c deposits in keratin tissues, so superficial infection
Tox: teratogenic, headache, confusion, CP450 inducer (Guiness…)
What is onchyomycosis treated with?
terbinafine that inhibits squalene epoxidase so can’t’t make ergosterol.
It is toenail fungus
