Clinical Mycology Flashcards
Where is a person most likely to get histoplasmosis?
Mississippi and Ohio River valleys
What disease does Histoplasmosis cause?
pneumonia
What is unique about where histoplasmosis stays in the body?
histoplasmosis hides WITHIN macrophages
How can a person get histoplasmosis?
bird or bat droppings
Where is a person most likely to get blastomycosis?
states east of Mississippi River and Central America
What disease does blastomycosis cause?
inflammatory lung disease and can disseminate to skin and bone
What is a characteristic of blastomycosis replication?
broad based budding
Where is a person most likely to get coccidioidomycosis?
Southwestern United States, California
What disease does coccidioidomycosis cause?
pneumonia
meningitis
disseminate to bone and skin
Coccidioidomycosis is unique in that is not a yeast. Instead, it takes what shape?
spherule
After what natural disaster will cases of coccidioidomycosis increase?
earthquakes (spores in dust thrown up in the air)
Where is a person most likely to get paracoccidioidomycosis?
Latin America
What is the characteristic formation of paracoccidioidomycosis?
“captain’s wheel” formation
List the systemic mycoses
histoplasmosis blastomycosis coccidioidomycosis paracoccidioidomycosis cutaneous mycoses
What is the causative microorganism of Tinea versicolor?
Malassezia furfur
How does Malassezia furfur cause hypo pigmentation or hyper pigmentation?
degradation of lipids –> acids that damage melanocytes –> hypo pigmentation or hyper pigmentation
What is the treatment for Tinea versicolor?
topical miconazole selenium sulfide (Selsun)
What is the characteristic appearance of Malassezia furfur?
“spaghetti and meatball” appearance
What is the treatment for other tinea (e.g. tinea pedis, tinea curries, tinea carpers, tinea capitis)?
ketoconazole
List the opportunistic fungal infections
Candida albicans Aspergillus fumigatus Cryptococcus neoformans Mucor and Rhizopus spp. Pneumocystis jirovecii Sporothrix schenckii
What diseases are caused by Candida albicans?
oral and esophageal thrush in IC pts vulvovaginitis diaper rash endocarditis in IV drug users disseminated candidiasis chronic mucocutaneous candidiasis
What is the treatment for Candida albicans infection?
topical azole for vaginal
fluconazole or caspofungin for oral/esophageal
fluconazole, amphotericin B, or caspofungin for systemic
What patients are most susceptible to Aspergillus fumigatus infections?
IC pts (chronic steroids and transplant patients) chronic granulomatous disease
Allergic bronchopulmonary aspergillosis (ABPA) is associated with which diseases?
asthma and cystic fibrosis
When are aspergillomas most commonly seen?
after a TB infection
What is a characteristic of Aspergillus fumigatus
septate hyphae that branch @ 45 degree angles
Aflatoxins produced by Aspergillus are associated with what cancer?
hepatocellular carcinoma
Where is Cryptococcus neoformans most often found?
soil and pigeon droppings
What lesion is indicative of a cryptococcus neoforms infection in the brain?
“soap bubble” lesions in the brain
What group of people is Mucor and Rhizopus spp. infection most commonly seen?
ketoacidotic diabetic and leukemic patients
What is the pathogenesis of mucormycosis?
excess ketone and glucose –> fungi proliferate in blood vessel walls –> penetrate cribriform plate –> enter brain
What area of the brain is most affected by mucormycosis?
frontal lobe (location of abscesses)
What are symptoms of mucormycosis infection?
HA
facial pain
black necrotic eschar on face
may have cranial nerve involvement
What is the treatment for mucormycosis infection?
amphotericin B
What disease is caused by Pneumocystic jirovecii?
Pneumocystis pneumonia (PCP), a diffuse interstitial pneumonia
What patients is Pneumocystic jirovecii infection most commonly seen?
IC pts (e.g. AIDS)
Disc shaped yeast forms on methenamine silver stain of lung tissue indicates what type of infection?
Pneumocystic jirovecii infection
What is the treatment/prophylaxis for PCP infection?
TMP-SMX (1st line)
pentamidine (if pt has a sulfa allergy)
dapsone (prophylaxis only)
atovaquone (prophylaxis only)
When should you start prophylaxis for PCP in an IC pt?
when CD4 count drops <200 cells/mm3 in HIV pts
Where is Sporothrix schenckii found?
vegetation
What are physical characteristics of Sporothrix schenckii?
dimorphic, cigar-shaped budding yeast
What is the pathogenesis of Sporotrichosis (infection from Sporothrix schenckii)?
spores introduced into the skin (typically by a thorn) (a.k.a. rose gardener’s disease) –> local pustule or ulcer with nodules along draining lymphatics (ascending lymphangitis)
What is the treatment for Sporotrichosis?
itraconazole or potassium iodide
