DIT Mycology

Question 1

Classic scenario of pancreatic cancer in head of pancreas?

Answer 1

50 year old man with painless jaundice

Question 2

Presentation of candidal esophagitis?

Answer 2

AIDS, leukemia, lyphoma

Painful swallowing with substernal chest pain and feeling of obstruction when swallowing

Question 3

Describe vulvovaginitis with candida

Answer 3

diabtic or after antibiotic

Severe itching, edema, discharge
ACIDIC pH

Question 4

Disseminated candidiasis can attack patients where?

Answer 4

Anywhere! it spreads and is dangerous. Endocarditis in IV drug users is possible but can really hit anything

Question 5

Dx and tx of candidiasis?

Answer 5

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

Question 6

What is attacked by cryptococcus? Where is it from?

Answer 6

Cryptococcus is meningitis in AIDs patients

Found in pigeon shit and soil

Question 7

Cryptococcal diagnosis (buzzword city)

Answer 7

Soap bubble imaging in brain
Latex agglutination (b/c capsule)
muCiCaramine (CryptoCoCCus)
India Ink

Question 8

Tx cryptococcal meningitis?

Answer 8

Amphotericin B and flucytosine followed by fluconazole

Question 9

Stain for PCP?

Imaging?

Answer 9

Silver stain

Ground glass appearance of interstitial infiltrates

Question 10

Tx for PCP if sulfa allergy?

Answer 10

Pentamidine and clindamycine + primaquine (dapsone for prophylaxis if sulfa allergy)

Question 11

Aspergillus can cause what?

Answer 11

Allergic bronchopulmonary with asthma or CF

Aspergillomas in lung cavities

Aflatoxin for hepatoccelular carcionma

Invasive in immunocompromised or CHRONIC granulomatous disease

Question 12

Dx of aspergillus? know!

Answer 12

A for Acute Angles in Aspergillus. not dimorphic

Question 13

Who is affected by Mucor and Rhizopus?

Dx?

Answer 13

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

Question 14

Presentation of mucor?

Tx

Answer 14

Rhinocerebral. Facial pain and headache with large necrotic lesions (black escar)

CN deficits and blindness

Dx: tissue biopsy

Tx: debridement and amphotericin B

Question 15

What are the three primary causes of pruritic skin fungus?

Dx:

Answer 15

skin MET skin and spread it

Microsporum
Trichophyton
Epidermophyton

Mold hyphae in KOH prep

they can cause ringworm and onychomycosis

Question 16

Hypopigmented spots on shoulders andstuff (think on kids at pools) are caused by what?

Tx?

Answer 16

Tinea versicolor (changes skin COLOR). Malassezia furfur

Degrades lipids and stuff and makes skin hyper or hypo pigmented

Azoles or topical selenium sulfide

Question 17

What looks like spaghetti and meatball on KOH prep?

Answer 17

Tinea versicolor (malasssezia furfur). The hyperpigmented spots

Question 18

Opportunistic fungal infections?

Answer 18

Candidiasis
Aspergillus
Cryptococcus
Mucor and Rhizopus

Question 19

3 question warmup. Organism with following statements? (not fungus)

Cat scratch
Cat bite
Cat shit
Puppy shit
Animal urine

Answer 19

Cat scratch: bartonella
Cat bite: pastuerella m
Cat shit: toxoplasma
Puppy shit: yersinia enter..
Animal piss: leptospira or hantavirus if mouse pee

Question 20

Localized mycoses tx?

Severe or disseminated or complicated infection tx?

Answer 20

Azoles for most localized or uncomplicated

Amphotericin B for severe

Question 21

Granulomas seen with mycoses?

Answer 21

Non-caseating granulomas (one way to differentiate from TB)

Question 22

What diseases are associated with birds?

Answer 22

HIsto
Cryptococcus (pigeon)
Chlamydophila psititaci
H5N1
West Nile

Question 23

Patient was spelunking and has pulmonary infection. Disease? What does it look like? What region do you find it?

Answer 23

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)

Question 24

Blasto affects what? What does it look like?

Answer 24

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)

Question 25

Where is blasto geographically?

Answer 25

Mississippi valley from central america to canada

Question 26

What does coccidio look like? Where is it geographically?

Answer 26

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)

Question 27

Coccidio symptoms?

Answer 27

usually asymptomatic or mild

Can be severe pneumo
Can disseminate to CNS bone and skin (skin most common dissemination)

Question 28

What does paracoccidiomycosis look like? Where is it geographically?

What symptoms can it cause?

Answer 28

Paracoccidiomycosis PARAsails with CAPTAINs week all the way to Latin America

Captain wheel

Severe pneumonia

Question 29

What is sporothrix associated with? what does it look like?

Symptoms?

Answer 29

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

Question 30

Tx of sporothrix? mnemonic

Answer 30

ITraconazole or potassium iodid

plant a ROSE in a POTassium iodide

Question 31

Amphotericin B mechanism?

tox? (one is super important to know and how to limit it)

Answer 31

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

Question 32

Nystatin mechanism? Use?

Tox

Answer 32

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

Question 33

Azoles mechanism?

Answer 33

inhibit ergosterol synth by blocking P450

Question 34

Fluconazole use?

Answer 34

Crosses BBB.

Cryptococcal meningitis prophylaxis in AIDs

Also candidal

Question 35

Side effects of azoles?

Answer 35

Block cyp450 (so hepatotoxicity AND… less testosterone production: Gynecomastia)

Elevated liver enzymes

Question 36

Mechanism of flucytosine?

Use?

Tox?

Answer 36

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

Question 37

What are the echinocandins?

Mechanism?

Use

Tox?

Answer 37

-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)

Question 38

Terbinafine mechanism?

Use?

Tox?

Answer 38

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

Question 39

Griseofulvin mechanism?

Why it is useful?

Tox?

Answer 39

Interferes with microtubule function. Disrupts mitosis.

Good b/c deposits in keratin tissues, so superficial infection

Tox: teratogenic, headache, confusion, CP450 inducer (Guiness…)

Question 40

What is onchyomycosis treated with?

Answer 40

terbinafine that inhibits squalene epoxidase so can’t’t make ergosterol.

It is toenail fungus