1 Usmle Micro - Fungus

Front 1

SYSTEMIC MYCOSES

Caused by what?
Dz?
Tx

Back 1

DIMORPHIC FUNGI
Cold = 20°C = MOLD
Heat = 37°C = YEAST

Dz = PNA ± DISSEMINATE
★ can mimic TB (GRANULOMA formation)
-- X NO person-person transmission

Tx:
LOCAL = FLUCONAZOLE / KETOCONAZOLE
SYSTEMIC = AMPHOTERICIN B

Front 2

HISTOPLASMOSIS

ENDEMIC LOCATION
PATHOLOGIC Fts

Back 2

HISTOPLASMOSIS

Endemic in: Mississippi & Ohio river valleys
-- BIRD / BAT droppings

Pathologic Fts:
① PNA
② Histo HIDES w/in macrophages (smaller than RBC)

Front 3

BLASTOMYCOSIS

ENDEMIC LOCATION
PATHOLOGIC Fts

Back 3

BLASTOMYCOSIS

Endemic in: EAST of Mississippi River & Central America.

Pathologic Fts:
① INFLAMMATORY LUNG dz
② can disseminate → SKIN & BONE
③ forms GRANULOMATOUS NODULES
④ Blasto Buds Broadly (same size as RBC)

Front 4

COCCIDIODO-MYCOSIS

ENDEMIC LOCATION
PATHOLOGIC Fts

Back 4

COCCIDIODO-MYCOSIS

Endemic in: SW US, CA (San Joaquin Valley)

Pathologic Fts:
① PNA
② MENINGITIS
③ can disseminate → SKIN & BONE
④ ↑case rate after EARTHQUAKES
-- d/t SPHERULES filled w/ ENDOSPORES (>> RBCs) in dust → air

Front 5

PARA-COCCIDIOIDO-MYCOSIS

ENDEMIC LOCATION
PATHOLOGIC Fts

Back 5

PARA-COCCIDIOIDO-MYCOSIS

Endemic in: LATIN America

Pathologic Fts:
① BUDDING yeast
② "CAPTAIN's WHEEL" formation (>> RBCs)

Front 6

TINEA VERSICOLOR

ENDEMIC LOCATION
PATHOLOGIC Fts
Tx

Back 6

MALASSEZIA FURFUR (cutaneous mycoses)

Endemic in: HOT, HUMID weather

Pathologic Fts:
① LIPID degradation → acids → damage MELANOCYTES →
② HYPO / HYPER-PIGMENTED PATCHES
KOH prep = "Spaghetti & Meatball" appearance

Tx = MICONAZOLE, SELENIUM sulfide

Front 7

TINEA

TYPES of TINEA
CAUSATIVE ORGANISMS
PATHOLOGIC Fts
Tx

Back 7

Types of TINEA =
● PEDIS = FOOT
● CRURIS = GROIN
● CORPORIS = RINGWORM on BODY
● CAPITIS = HEAD, SCALP

Caused by DERMATOPHYTES =
① MICROSPORUM
② TRICHOPHYTON
③ EPIDERMOPHYTON

Front 8

TINEA

PATHOLOGIC Fts
Tx

Back 8

Pathologic Fts:
① PRURITIC lesions w/ CENTRAL CLEARING resembling a RING
② KOH prep = MOLD HYPHAE, not dimorphic
③ PETS = reservoir for MICROSPORUM
→ Rx topical -AZOLES

Front 9

OPPORTUNISTIC FUNGAL INFX

List the organisms

Back 9

[CCAMPS]

CANDIDA albicans
CRYTOCOCCUS neoformans
ASPERGILLUS fumigatus
MUCOR & RHIZOPUS spp
PNEUMOCYSTIS jiroveci
SPOROTHRIX schenckii

Front 10

CANDIDA ALBICANS

STRUCTURE / Dx
Dz caused

Back 10

Structure / Dx:
① DIMORPHIC
② PSEUDOHYPHAE in 20°C culture
③ GERM TUBE formation @ 37°C = Dx

Dz caused:
(1.) Oral & esophageal THRUSH in IC (neonates, steroids, DM, AIDS)
(2.) VULVOVAGINITIS -- in DM, Abx use
(3.) ENDOCARDITIS in IVDU
(4.) Chronic MUCOCUTANEOUS CANDIDIASIS
(5.) DISSEMINATED CANDIDIASIS (any organ)

Front 11

Tx for CANDIDA ALBICANS?

Back 11

Superficial infx: NYSTATIN

Systemic: AMPHOTERICIN B

Front 12

CRYPTOCOCCUS NEOFORMANS

STRUCTURE / Dx

Back 12

(1.) YEAST w/ WIDE CAPSULAR HALO
(2.) NARROW-based UNEQUAL BUDDING
(3.) LATEX AGGLUTINATION
-- detects polysaccharide CAPSULAR Ag (↑Sp)
(4.) culture on SABOURAUD's agar & INDIA INK stain
(5.) NOT dimorphic

Front 13

CRYPTOCOCCUS NEOFORMANS

Source
Dz caused

Back 13

Source = SOIL, PIGEON DROPPINGS

Dz caused:
(1.) MENINGITIS
(2.) CRYPTOCOCCOSIS
(3.) "SOAP BUBBLE" lesions in brain

Front 14

ASPERGILLUS FUMIGATUS

STRUCTURE / Dx
Dz caused

Back 14

Structure / Dx:
(1.) MOLD
(2.) SEPTATE HYPHAE that branch at Acute Angles (≤45°)
(3.) rare FRUITING bodies
(4.) NOT dimorphic

Dz caused:
(1.) ALLERGIC Broncho-pulmonary ASPERGILLOSIS
(2.) LUNG CAVITY ASPERGILLOMA = "FUNGUS BALL"
(3.) INVASIVE aspergillosis
-- esp in IC & Pt w/ Chronic Granulomatous dz

Front 15

MUCOR & RHIZOPUS spp

STRUCTURE / Dx
PATHOPHYS

Back 15

Structure / Dx:
(1.) MOLD
(2.) IRREGULAR broad nonseptate HYPHAE
(3.) branch at Wide angles (≥90°)

Pathophys:
Dz mostly in DKA & LEUKEMIA Pts

Proliferate in blood vessel WALLS when excess KETONE & Glc
→ penetrate CRIBIFORM PLATE → enter BRAIN

Front 16

MUCOR & RHIZOPUS spp

Clinical Fts

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Dz caused = MUCORMYCOSIS
(1.) RHINOCEREBRAL, FRONTAL lobe ABSCESSES
(2.) HA
(3.) Facial pain

Black necrotic ESCHAR on face
CN involvement

Front 17

PNEUMOCYSTIC JIROVECI

STRUCTURE / Dx
Dz caused

Back 17

Structure / Dx:
(1.) YEAST - SAUCER-shaped
(2.) DIFFUSE BILATERAL CXR
(3.) Dx = LUNG Bx / LAVAGE →
(4.) METHENAMINE SILVER stain

Dz caused:
(1.) DIFFUSE INTERSTITIAL PNA
(2.) most infx = ASx
(3.) IC predisposes to dz

Front 18

PNEUMOCYSTIC JIROVECI

TREATMENT

Back 18

① TMP-SMX
② PENTAMIDINE
③ DAPSONE

★ Start PPx in HIV when CD4 <200 cells/ml

Front 19

SPOROTHRIX SCHENCKII

STRUCTURE / Dx

Back 19

Structure / Dx:
(1.) DIMORPHIC FUNGUS
(2.) CIGAR-shaped yeast forms
(3.) UNEQUAL budding
(4.) lives on VEGETATION

Front 20

SPOROTHRIX SCHENCKII

Dz caused
TREATMENT

Back 20

Dz caused:
(1.) SPOROTRICHOSIS
(2.) ROSE GARDENER's dz - traumatically introduced into skin by THORN
-- LOCAL PUSTULE / ULCER w/
-- NODULES along draining lymphatics = ASCENDING LYMPHANGITIS
(3.) Little systemic illness

Treatment:
① ITRACONAZOLE or
② POTASSIUM IODIDE