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Flashcards in Mycoses Deck (79)
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1
Q

systemic mycoses - appearance

A

all dimorphic fungi
(EXCEPT COCCIDIOIDOMYCOSIS –> SPHERULE - NOT YEAST IN TISSUE)
cold (20c) –> mold
heat (37c) –> yeast

2
Q

systemic mycoses -treatment . they can mimic

A

local infection: fluconazole or intraconazole
systemic infection: amphotericin B
they can mimic: TB (granouloma formation)
except, unlike TB, no peroson to person transmission

3
Q

systemic mycosis - area (map)

A
  1. Histoplasmosis –> Mississippi and Ohio River valleys
  2. Blastomycosis –> Eastern US and Central America
  3. Coccidioidomycosis –> Southwestern US, California
  4. Paracoccidioidomycosis –> Latin America
4
Q

systemic mycosis - size vs RBC

A
  1. Histoplasmosis - smaller
  2. Blastomycosis - same
  3. Coccidioidomycosis - much larger
  4. Paracoccidioidomycosis - much larger
5
Q

Histoplasmosis - source / causes

A

Bird or bat dropping

- pneumonia and erythema nodosum

6
Q

patient with suspected sarcoidosis deteriorates after steoroids

A

HIstoplasma

7
Q

histoplasmosis - unique signs / symptoms / diagnosis

A

palatal/tongue ulcers / splenomegaly

- urine / serum antigen

8
Q

Blastomycpsis - clinical features

A

lung: acute + chronic pnneumonia
2. skin: wartlike lesions, violacceous nodules, skin ulcers
3. Bone: osteomyelitis
4. GI: prostatis, epidiymo-orchitis
5. CNS: meningitis, epidural or brain abscess
GRANOULOMAS

9
Q

Coccidioidomycosis causes / treatment

A

enedemic mycosis of southwest desert –> CAP often accompanied by arthralgias, erythema nodosum, erythema multiforme –> symptoms may last weeks to months –> no treatment for healty patients –> ketoconazole or fluconazole for patients with risk for dissemination (immunocompromised)
(VALLEY FEVER)

10
Q

Coccidioidomycosis - case rate increases after … (WHY)

A

earthquakes (spores in dust thrown into air –> inhaled –> spheruls in lung

11
Q

Coccidioidomycosis is also called

A

Valley fever

12
Q

Paracocciddioidomycosis under the microscope

A

Budding yeast with “captain’s wheel formation

much larger than RBCs

13
Q

systemic mycosis - erythema nodosum

A
  1. Coccidioidomycosis

2. Histoplasmosis

14
Q

systemic mycosis - under the microscope

A
  1. Histoplasmosis –> Macrophages filled with Histoplasma
  2. Blastomycosis –> Broad-base budding
  3. Coccidioidomycosis –> spherule filled with endospores
  4. Paracoccidioidomycosis –> captain wheel
    - -> shines
15
Q

Cutaneous mycoses are divided to

A
  1. tinea (dermatophytoses)

2. tinea versicolor

16
Q

Dermatohytes - appearance / include …

A

branching septate hyphae visible on KOH preparation with blue fungal stain

  1. Microsporum
  2. Trichophyton
  3. Epidermophyton
17
Q

Cutaneous mycoses - types

A
  1. tinea capitis (dermatophytoses)
  2. tinea corporis (dermatophytoses)
  3. tinea cruris (dermatophytoses)
  4. tinea pedis (dermatophytoses)
  5. tinea unguium (dermatophytoses)
  6. Tinea versicolor
18
Q

Tinea capitis occurs on (area of the body) / symptoms

A
  • head scalp
    1. lympadenopathy
      1. alopecia
      2. scaling
19
Q

Tinea corporis - area of the body / symtpoms

A

torso (κορμός)

erythematous scaling rings (ringworm) and central clearing

20
Q

Tinea corporis can be acquired from

A

contact with an infected cat or dog

21
Q

Tinea cruris - occur in (area of the body) / symptoms

A

inguinal area

rash in the inguinal area without the central clearing seen in the tinea corporis

22
Q

Tinea unguium - is also called / area of the body

A

onychomycosis

nails

23
Q

Tinea pedis - how many varieties and which (MC) / AKA

A
  1. interdigital (MC)
  2. Moccasin distribution
  3. Vesicular type (blister)
    AKA: athlete’s foot
24
Q

Tinea versicolor is caused by

A

Malassezia spp (Pitirosporum spp)

25
Q

Tinea versicolor - whether

A

any time of year but common in summer (hot, humid weather)

26
Q

Tinea versicolor - under microscopy / treatment

A

spaghetti and meatballs

    1. topical and/oral antifungul medication
      1. selenium sulfate
27
Q

opportunistic fungal infections - bugs?

A
  1. Candida ablicans
  2. Aspergillus Fugimatus
  3. Cryptococcus neoformans
  4. Mucor and Rhizopus spp.
  5. Pneumocystis jirovecii
  6. Sporothrix schenckii
28
Q

Candida ablicans causes …. (and situations)

A
  1. Oral and esophageal thrush (immunocompromised –> neonates, steroids, diabetes, AIDS)
  2. vulvovaginitis (diabetes, antibiotics)
  3. diaper rash
  4. endocarditis (iv drug users)
  5. disseminated candidiasis
  6. chronic mucocutaneous candidiasis
  7. osteomyelitis (IV drugs)
29
Q

Candida ablicans - morphology

A

DIMORPHIC
pseudohyphae and budding yeast at twenty c.
germ tubes at thirty seven c

30
Q

Candida ablicans - treatment

A

topical azole for vagina
nystatin, fluconazole or caspofungin for oral/esophageal
fluconazole or amphotericin B for systemic

31
Q

Aspergillus fugimatous causes … (and situations)

A
  1. invasive aspergillosis (immunocompromised and with chronic granulomatous disease)
  2. Allergic bronchopulmonary aspergillosis (associated with asthma, cystic fibrosis) –> bronhiectasia and eosinophilia
  3. Aspergillomas in lung cavitieus (esp after TB)
  4. produce aflatoxins –> hepatocellular CA
32
Q

Aspergillus fugimatous - morphology

A
NOT dimorphic (only as a mold)
Septate yphae that branches at 45 angle
conidophore with radiating chains of spores
33
Q

Cryptococcus neoformans causes / morphology

A
  1. meningitis
  2. cryptococcosis
  3. cryptococcal encephalitis
    - heavily encapsuled yeast. NOT DIMORPHIC
    5-10μm (NARROW BASED BUD)
34
Q

Cryptococcus neoformans is found in

A

soil

pigeon dropping

35
Q

Cryptococcus neoformans - lab

A

Culture on Sabouraud agar
Stain with india ink and mucocarmine
latex agglutination test detects polysaccharide capsular antigen
soap bubble lesion in brain image (in cryptococcal encephalitis)

36
Q

Cryptococcus neoformans - lab - most specific test

A

latex agglutination test detects polysaccharide capsular antigen

37
Q

Rhino-orbital-cerebral mucormycosis - manifestation

A

Acute/aggresive
fever, nasal congestion, purulent nasal discharge, headache, sinus pain
NECROTIC invasion of palate, orbit, brain

38
Q

Mucormycosis - pathophysiology / diagnosis

A

fungi proliferation on blood vessel walls, pemetrate cribiform plate and enter brain
- sinus endoscopy with biopsy + culture

39
Q

Rhino-orbital-cerebral mucormycosis - RF

A
  1. DM (ketoacidosis)
  2. hematologic malign
  3. Solid organ or stem cell transplant
40
Q

Mucormycosis treatment

A
  1. surgical debridement
  2. liposomal amphotericin
  3. elimination of risk factors
41
Q

Mucor morphology

A

NOT DIMORPHIC

irregular, broad nonseptae hyphae at wide angles

42
Q

Pneumocystis jirevecii - morphology / originally classified as

A

yeast like fungus (disc shape)

originally classified as protozoan

43
Q

Pneumocystis jirevecii - start prophylaxis when

A

CD4 cound drops under 200 cells/mm3 in HIV patients

44
Q

sporothrichosis - manifestation

A

subacute / chronic

  • skin papule –> ulceratio nwith nonpurulent odorless drainage
  • proximal lesions along lymphatic chaein
  • lymphadenopahrym deepr spread and sysemic symptoms are RARE
45
Q

Sporothrix schenckii - morphology

A

Dimorphic, cigar shaped budding yeast that grows in branching hyphae with rosettes of conidia

46
Q

Sporothrix schenckii - treatment

A

3-6 months of oral intraconazole

47
Q

opportunistic fungal infections - dimorphic fungi

A
  1. Candida ablicans

2. Sporothrix schenckii

48
Q

Oppostunistic fungal infection - morphology of every fungus

A
  1. Candida ablicans - dimorphic: pseudohyphae and budding yeast at 20c. germ tubes at 37c
  2. Aspergillus Fugimatus - not dimorphic (only as a mold). Septate hyphae that branches at 45 angle
    conidophore with radiating chains of spores
  3. Cryptococcus neoformans: heavily encapsuled yeast. not dimorphic, 5-10μm (NARROW BASED BUD)
  4. Mucor and Rhizopus spp: not dimorphic, irregular, broad nonseptae hyphae at wide angles
  5. Pneumocystis jirovecii: Disc-shaped yeast-like
  6. Sporothrix schenckii: Dimorphic, cigar shaped budding yeast that grows in branching hyphae with rosettes of conidia
49
Q

Histoplasma in HIV - RFs and prophylaxis

A

RF: CD less than 150, endemic area: Ohio and Misisipi river valley (bird or bat dropping)
prophylaxis: intraconazole

50
Q

progressive disseminated histoplasmosis - how to diagnose

A

urine or serum histoplasma antigen
also pancytopenia
- cultures takes 4-6 wks

51
Q

progressive dissaminated histoplasmosis - treatment

A

amphotericin B for 1 week –> after clinical improvement –> oral intraconazole for 1 year

52
Q

candida esoph - treatment

A

3-5 days fluconazole

53
Q

special characteristics on manifestation of cryptococcal meningitis

A

no neck stiffness
no photophobia
increased intracranial pressure

54
Q

Cryptococcal meingitis - treatment

A

IV amphotericin (+ fluticosine)
stop antiretroviral therapy for at least 2 weaks
maybe LPs to decreased pressure

55
Q

PCP pneumonia treatment

A

TMP-SXM

prednisone if low O2 levels less than 92% or PO2 less than 70 or arterial - alveolar gradient more than 35

56
Q

PCP - skin

A

nodular and papular cutaneous lesions of the external auditory meatus in immunocompromised patiends

57
Q

indications for adding corticosteroids to TMP-SXM in PCP treatment

A
  • Pa02 70 or lower

- A-a gradient 35 or more on room air

58
Q

PCP alternatives

A
  1. Pentamidine (IV)
  2. atovquone
  3. Timethoprim + dapsone
  4. Clindamycin (IV or oral) + primaquine (oral)
59
Q

PCP - workupe

A
  • LDL elevated
  • diffuse reticular infiltrates on imaging
  • BAL
60
Q

sporotrichosis - epidemiology

A
  • sporothrix schenckii (dimorphic fungus)
  • decaying plant matter / soil
  • darnders + landscapers
61
Q

Membrane pores formers - drugs - and mechasnim of action

A
  1. Amphotericin B 2. Nystatin
    Binds to ergosterol (unique to fungi) –> membranes pores that allow leakage of electrolytes
    (harmless for host cells)
62
Q

Amphotericin B - clinical use

A
  1. SERIOUS SYSTEMIC MYCOTIC INFECTIONS : Histoplasmosis, Blastomycosis, Coccidioidomycosis, Mucor, Candida, Cryptococcus
  2. Naegleria Fowleri
  3. Leismania Donovani
63
Q

Amphotericin B - meningitis

A
  • with/without flucytosine for cryptococcal meningitis

- Intrathecally for fungal meningitis

64
Q

Amphotericin B - administrate with (and why)

A

supplement K+ and Mg2+ because of altered renal tubule permeability

65
Q

Amphotericin B - toxicity

A
  1. fever/chills (shake and bake)
  2. Hypotenesion
  3. nephrotoxicity
  4. arrhythmias
  5. anemia
  6. IV phlebitis
66
Q

Amphotericin B - solution of toxicity

A
  1. Hydration decreases nephrotoxicity

2. Liposomal amphotericin –> decreased toxicity

67
Q

Nystatin - clinical use

A

TOPICAL USE ONLY (TOO TOXIC FOR SYSTEMIC USE)

  1. oral candidiasis (swish and swallow)
  2. topical for diaper rash or vaginal candidiasis
68
Q

Flucytosine - mechanism of action

A

Inhibits DNA and RNA biosynthesis by conversion to 5-fluorouracil by cytosine deaminase –> inhibits thymidylate synthetase

69
Q

Flucytosine - clinical use

toxicity

A

Systemic fungal infections (esp meningitis caused by Cryptococcus) in combination with amphotericin B
- Bone marrow suppression

70
Q

azoles - mechanism of action

A

inhibit fungal stero (ergosterol) synthesis by inhibiting the cytochrome P-450 enzyme that converts lanosterol to ergosterol (14-α-demethylase)

71
Q

azoles - clinical use

A

Local and less serious systemic mycoses:

  • Fluconazole: chronic suppression of cryptococcal meningitis in AIDS patients, all types of candidal infections, LOCAL systemic mycoses
  • Intraconazole: (LOCAL systemic mycoses) Blastomyces, Coccidioides, Histoplasma
  • Clotrimazole, miconazole: topical fungal infection
72
Q

Azoles - toxicity

A
  1. testosterone synthesis inhibition –> gynecomastia (esp ketoconazole)
  2. liver dysfunction (inhibits P450)
73
Q

Terbinafine - mechanism of action / clinical use

A

inhibits the fungal enzyme squalene epoxidase (Lanosterol synthesis inhibitor)
- Dermathophytes (esp onychomycoses)

74
Q

Terbinafine - toxicity

A
  1. GI upset
  2. headaches
  3. hepatotoxicity
  4. Taste disturbance
75
Q

Echinocandins - drugs and mechanism of action

A

Echinocandins –> 1. Anidulafungin 2. caspofungin
3. micafungin
inhibit cell wall synthesis by inhibiting synthesis of β-glucan

76
Q

Echinocandins - clinical use

A
  1. invasive aspergilosis

2. Candida

77
Q

Echinocandins - drugs and toxicity

A

Echinocandins –> 1. Anidulafungin 2. caspofungin
3. micafungin
GI upset, flushing (by histamine release)

78
Q

Griseofulvin - clinical use

A
  1. oral treatment of superficial infections

2. inhibits growth of dermatophytes (tinea, ringworm)

79
Q

Griseofulvin - toxicity

A
  1. teratogenic 2. carcinogenic 3. confusion 4. headaches 5. increased cytochrome P-450 and warfarin metabolism