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154 Cards in this Set
- Front
- Back
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antropophilic
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cause infections in humans
easily transmitted from humans to humans |
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zoophilic
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cause infections in animals
easily transmitted from animal to human zoophilic dermatophytes tend to develop a more inflammatory reaction when affecting humans than antropophilic |
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geophilic
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live as saprophytes in the soil
geophilic dermatophytes develop a strong inflammatory reaction in cases of ringworm most important: M. gypseum |
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ectrothrix
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arthoconidia formed outside of the hair
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endothrix
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arthoconidia formed inside the hair
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verrucous
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charaterized by the formation of warts
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pedunculated
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having a stalk
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sclerotic body
aka: definition |
sclerotic body, aka: meddlar body
round, thick-walled, pigmented cells divided by more than one plane |
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papule
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inflamed, red, tender bumps with no pus-filled head
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pustule
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inflamed, tender bump with pus-filled center and red border
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nodule
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large, hard bumps under skin surface
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Differentiate Eumycetomas from Actinomycetomas
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Eumyecetoma = caused by Black and hyaline fungi
Actinomycetomas - caused by filamentous bacteria: Nocardia, Streptomyces, Actinomadure |
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General signs of opportunisitic fungal and fungal-like organisms
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FUO
weight loss subcutaneous granulomas &/or disseminated granulomatous ds |
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characteristics of "active borders"
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raised
erythematous vesicular |
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Pitryiasis versicolor
snapshot |
scaling dermititis
lipophilic yeast normal skin microbiota |
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Pitryiasis versicolor
etiology |
genus: Malassezia
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Pitryiasis versicolor
epidemiology |
infection from normal skin microbiota
RFs: stress, oily skin |
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Pitryiasis versicolor
clinical features |
macula on torso, shoulders (areas of hypo- or hyperpigmentation)
pruritis or folliculitis sometimes observed does not elicit strong inflammation |
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Pitryiasis versicolor
lab diagnosis |
Wood's lamp to visualize macula
scrapings --> "spaghetti and meatballs" under microscope isolated by inoculating tubes of Sabouraud dextrose agar w/ surface olive oil |
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Pityriasis versicolor
treatment |
topical antimycotic: e.g.: ketoconazole
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Superficial candidiasis
snapshot |
chronic superficial fungal infection
caused by C. albicans or other Candida spp. normal GI tract microbiota |
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Superficial candidiasis
etiology |
C. albicans or other Candida spp.
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Superficial candidiasis
epidemiology |
opportunistic fungal infection
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Superficial candidiasis
clinical features |
depends on body region
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Thrush
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superficial candidiasis - mouth
chronic infection of oral and mucosal membranes white, creamy patches in mouth and tongue composed of C. albicans cells seen frequently in AIDS pts |
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Vulvovaginatis
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superficial candidiasis
pruritic, eczematoid lesions with vesicular borders and white pseudomembranes RFs: DM, pregnancy, BC pills, ABS tx |
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Cutaneous candidiasis
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superficial candidiasis
wet, erythematous lesions with active borders on skin RFs: bacterial ds, obesity, overexposure to moist environment |
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Onycomycosis
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superficial candidiasis of fingernails
seen in pts who work in wet conditions |
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Diaper candidiasis
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erythema in infants due to allergic reaction to urine --> C. albicans infections
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Superficial candidiasis
lab diagnosis |
clinical appearance
microscopy |
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Superficial candidiasis
treatment |
depends on type
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Dermatophytosis
snapshot |
superficial fungal infection of keratinized tissues
ringworm - "tinea" |
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dermatophytosis
etiology |
3 genera: Epidermophyton, Microsporum, Trichophyton
2 important species: - T. rubrum (tinea corporis, manuum, pedis) - E. floccosom (tinea cruris) |
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Dermatophytosis
Epidemiology |
antrophilic
zoophilic geophilic - depending on infecting species |
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Dermatophytosis
clinical features |
lesions named after infected body part
ringworm lesions are circular in shape (formed when initial inflammation forces dermatophyte away) prevalence in children over adults |
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Tinea barbae
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Trichophyton infection
ecto- and endothrix seen zoonotic forms --> severe inflammation with pustular folliculitis |
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Tinea capitis
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dermatophytosis of scalp
ecto- and endothrix seen |
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Tinea corporis
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ringworm of trunk, shoulders, limbs, face
lesions: annular, scaly patches with active borders T. rubrum |
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Tinea cruris
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ringworm of groin, perianal area, genitalia
lesions: annular, scaly patches with active borders E. floccosum |
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Tinea manuum
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hyperkeratosis of hand
T. rubrum |
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Tinea pedis
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athlete's foot
acute cases - vesicles and pustules chronic - hyperkeratosis and squamous scales on skin T. rubrum |
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Tinea unguium
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invasion of the nail by dermatophytes
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Dermatophytosis
lab diagnosis |
all dermatophytes have same parasitic stage:
mycelium with arthrospores |
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Dermatophytosis
treatment |
itraconazole
ketoconazole |
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Phaeohyphomycosis
snapshot |
fungal infection of deep dermis
caused by dematiaceous (black) fungi systemic infections may occur, but are rare |
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Phaeohyphomycosis
etiology |
Exophiala
Curvularia Bipolaris |
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Phaeohyphomycosis
epidemiology |
dematiaceous fungi found in soil and plant detritus
infectious acquired through traumatic implantation of fungi into skin |
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Phaeohyphomycosis
clinical features |
cutaneous and subcutaneous abscesses, granulomas and cysts
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Phaeohyphomycosis
lab diagnosis |
biopsies --> dark brown hyphae under microscope w/ 10% KOH
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Phaeohyphomycosis
treatment |
surgical excision of lesions
common antifungal drugs ineffective recurrence common |
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Chromoblastomycosis
snapshot |
chronic infection involving skin and subcutaneous tissue
dematiaceous fungi |
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Chromoblastomycosis
etiology |
4 dimorphic genera:
Cladophialophora Phialophora Fonsecaea Rhinocladiella |
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Chromoblastomycosis
epidemiology |
propagules (infecting units) introduced from soil by traumatic inoculation
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Chromoblastomycosis
clinical presentation |
Gold standard: sclerotic bodies in infected tissue
lesions occur mostly on extremities lesions are verrous, pedunculated (cauliflower like) flat, annular plaques also seen dissemination to other organs rare |
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Chromoblastomycosis
lab diagnosis |
sclerotic bodies
pseudoepitheliomatous hyperplasia in infected tissues |
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Chromobastomycosis
treatment |
surgical excision
antifungal Rx - limited efficacy |
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Sporotrichosis
snapshot |
chronic subcutaneous infection
caused by Sporothrix schenchii spreads via lymphatics to other skin areas systemic ds rare - caused by inhalation |
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Sporotrichosis
etiology |
Sporothrix schenckii - dimorphic, geophilic fungus
infection via traumatic inoculation |
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Sporotrichosis
epidemiology |
common in patients who work with thorny plants
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Sporotrichosis
clinical features |
primary cutaneous sporothricosis
- papule, pustule, or nodules - may eventually ulcerate lymphatic spread from 1* lesion is common |
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Sporotrichosis
lab diagnosis |
10% KOH is NOT reccommended b/c of LOW CONCENTRATIONS
Giemsa or Gram stains Splendore-Hoeppli material skin test differentiates from cutaneous leishmaniasis |
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Sporotrichosis
treatment |
saturated potassium iodide (KI) applied topically
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Mycetoma
snapshot |
crhonic localized infections of skin, subcutaneous tissues, and bones
swelling, tumor like lesions with draining sinus tracts containing small, "sulfur" grains Eumycetomas similar to acintomycetomas |
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Mycetoma
etiology |
most common genera:
Madurella Pseudoallescheria Fusarium |
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Mycetoma
epidemiology |
usually found in soil
acquired by traumatic inoculation found worldwide, but usually in tropics |
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Mycetoma
clinical features |
tumor-like masses with sinus tracts containing white or black granules (sulfur granules)
more frequent on extremities - cause deformity of affected structures |
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Mycetoma
lab diagnosis |
grains can be visualized grossly
chronic inflammatory reactions around granules granules usually surrounded by Splendore-Hoeppli phenomenon |
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Mycetoma
treatment |
granules must be identified by culture as bacteria or fungi
- actinomycetomas respond to ABS - eumycetomas do not respond to antifungal therapy amputation of affected area common |
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Blastomycosis
snapshot |
North American blastomycosis, Gilchrist's disease
(sub)clinical URT infection disseminates to other organs, including skin results when alveolar macrophages fail to eliminate fungus from lungs yeast in lungs --> progressive pulmonary infection w/ hematogenous spread |
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Blastomycosis
etiology |
Blastomces dermatitidi (dimorphic)
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Blastomycosis
epidemiology |
not common in U.S.
found in Africa, Middle East, India |
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Blastomycosis
clinical features |
respiratory symptoms!
fever, weight loss, fatigue 25% pts have bone involvement other sites dissemination: CNS, GU tract, URT, skin |
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Blastomycosis
lab diagnosis |
URT samples, pus from skin lesions, biopsies
Giemsa or 10% KOH spherical, thick-walled yeast with broad-based buds serological tests |
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Blastomycosis
treatment |
Amphotericin B
for meningitis - intrathecal injections Amphothericin B Ketoconazole, intraconozole, fluconazole also used Ketoconazole contraindicated in immunocompromised pts |
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Coccidioidomycosis
snapshot |
Valley fever, Posada's disease
sub/clinical infection of respiratory tract disseminates to other organs, including skin inhabits dry areas, like deserts ONLY in Americas |
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Coccidioidomycosis
etiology |
Coccidioides immitis and C. posadasii (both dimorphic)
infectious arthroconidia inhaled --> spherules w/ endospores in tissue endopsores released in vivo --> repeat cycle |
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Coccidioidomycosis
epidemiology |
C. immitis and posadasii occur in desert soil
only 40% of infected people show symptoms dissemination occurs mostly in immunocompromised |
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Coccidioidomycosis
clinical features |
dry cough, fever, weight loss, general disability
rapid progression --> death w/in days resistant to macrophages T cell activation required to stop dissemination meningitis seen 16% patients other sites: LNs, bones, skin |
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Coccidioidomycosis
lab diagnosis |
immature and mature spherules w/ endospores
granulomatous lesions w/ spherules sphreical elements at different developmental stages (w/ silver stain) serological tests |
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Coccidioidomycosis
treatment |
for disseminated Coccidioidomycosis: Amphotericin B
for CNS involvement: intrathecal Amphotericin B management with fluconazole and intraconazole 6-12 months relapses are common |
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Paracoccidioidomycosis
snapshot |
S. American Bastlomycosis or Lutz-Splenore-Almeida disease
chronic, progressive, granulomatous infection - disseminates systemically from lungs early stages resemble blastomycosis & coccidioidomycosis |
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Paracoccidioidomycosis
etiology |
Paracoccidioides brasiliensis
geophilic, dimorphic fungus w/ septate hyphae and microconidia in soil yeast w/ multiple buds in tissue |
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Paracoccidioidomycosis
epidemiology |
restricted to Latin American and rare even there
acquired by inhalation |
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Paracoccidioidomycosis
clinical features |
mucocutaneous lymphangitis infections - healthy adults
- progressive destruction palate, gingiva, nose -cervical LNs enlarged -dissemination to skin -generalized dissemination to LNs, spleen, intestine, liver progressive, fulminant disease in adolsescents and immunocompromised pts |
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Paracoccidioidomycosis
lab diagnosis |
10% KOH --> round yeast w/ multiple buds
serological tests cultures confirm findings |
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Paracoccidioidomycosis
treatment |
Amphotericin B
ketoconazole and intraconazole to prevent relapses |
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Histoplasmosis
snapshot |
Darling's disease
lungs, liver, spleen, bone marrow, lymphatics occurs in apparently healthy individuals dormant infections may reactivate during periods of immunosuppression |
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Histoplasmosis
etiology |
Histoplasma capsulatum
dimorphic, geophilic |
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Histoplasmosis
epidemiology |
HISTPLASMOSIS:
soil around chicken houses, bats, birds disease most common in Miss. and Ohio valleys 90% cases subclinical |
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Histoplasmosis
clinical features |
vary depending on severity: acute, subacute, chronic, progressive
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Acute histoplasmosis
clinical features |
mostly infants, children
high fever, N/V, diarrhea later: dry cough, SOB neutrophenia --> bacterial infection thromobytopenia --> bleeding heatomegaly, enlarged LNs blood culture usually positive |
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Subacute disseminated histoplasmosis
clinical features |
adults w/ long-lasting moderate fever
weight loss, weakness hepatosplenomegaly |
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Chronic disseminated histoplasmosis
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usual form in non-immunosuppressed adults
may develop acute form if immune system depressed intermittent fever, wight loss, chronic fatigue hepatomegaly 50% cases endocarditis, meningitis, subcutaneous nodules, skin lesions |
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Progressive disseminated histoplasmosis
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usually in immunocompromised patients
progressive disease w/ fever, hepatosplenomegaly, multi-organ failure |
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Acute histoplasmosis
lab diagnosis |
blood cultre almost always positive
bone marrow or LN biospy = best samples numerous yeast cells seen only w/in histiocytes; lymphocytes not abundant |
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Subacute histoplasmosis
lab diagnosis |
intracellular small yeast cells w/in macrophages is indicative
blood smears positive 50% cases liver tissue positive 80% caes |
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Histoplasmosis
treatment |
Amphotericin B
itraconozole for patients who don't tolerate amphotericin B |
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Systemic candidiasis
shapshot |
rare, chronic condition
terminal event in immunocompromised individuals endocarditis, meningitis, etc. septicemia common |
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Systemic candidiasis
etiology |
C. albicans most frequent
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Systemic candidiasis
epidemiology |
Candida part of normal microbiota
infection occurs when yeast form develops germ tubes and mycelium penetrates tissues |
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Systemic candidiasis
clinical features |
depend on infected organs
disseminated candidasis may resemble other mycotic infections |
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Systemic candidiasis
lab diagnosis |
infected tissues Gram stained or 10% KOH
culture ID helps |
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Systemic candidiasis
treatment |
Amphotericin B
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Cryptococcosis
snapshot |
Busse-Buschke's Disease
chronic, subacute, acute pulmonary, systemic and meningitic infection caused by yeast with capsule rare in immunocompetent |
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Cryptococcosis
etiology |
Cryptococcus neoformans (encapsulated yeast)
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Cryptococcosis
epidemiology |
C. neoformans found in soil w/ pigeon droppings
yeast forms inhaled into lungs primary lesions remain localized or may disseminate C. neoformans has special tropism for CNS |
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Pumonary cryptococcosis
clinical features |
most cases asymptomatic
cough, low fever, weight loss |
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CNS involvement in cryptococcosis
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usual form of cryptococcosis
meningitis (most common) meningocephalitis, cryptococcoma (tumor like masses in brain) |
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Cutenous and mucocutaneous cryptococcosis
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dissemination of yeast from lungs to skin or mucous membranes
papules, pustures, abscesses that ulcerate cutaneous inoculation and osseous involvement exist, but are rare |
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Cryptococcosis
lab diagnosis |
examination of spinal fluid - centrifuged and in India ink
budding yeast cells w/ prominent capsule indicate cryptococcosis deep scrapings from cutaneous lesions or biopsy from internal organs serologic tests recommended |
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Cryptococcosis
treatment |
Amphotericin B - initial tx
pts treated for life with fluconzole or intraconzole |
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Aspergillosis
snapshot |
infection of lungs
disseminates to other organs common in immunocompromised |
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Aspergillosis
etiology |
several species of Aspergillus
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Aspergillosis
epidemiology |
normal lab/hospital contaminant (nocosomial infection)
conidias inhaled; develop germ tubes and septate hyphae in immunocompromised |
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Aspergillosis
clinical features |
fever, respiratory symptoms, SOB, CP
lung cavities filled with ball-like mass of hyphal element dissemination to CNS, kidneys increasingly frequent endocarditis w/ arrthymias should be check to R/O aspergillosis |
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Aspergillosis
lab diagnosis |
sepate hyaline hyphae
many cases diagnosed post-mortem w/ dissemination, extensive damage will eventually kill host culture required |
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Aspergillosis
treatment |
Amphotericin B at greatest dose tolerated
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Zygomycosis
snapshot |
acute infection of respiratory tract
infection dependent on failure of alveolar macrophages to eliminate initial fungal elements dissemination through blood vessels --> thrombosis |
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Zygomycosis
etiology |
various zygomycetes
most common: Rhizopus |
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Zygomycosis
epidemiology |
found in soil, in association w/ plant matter
normal contaminants of lab/hospital opprotunistic acquired by inhalation |
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Zygomycosis
clinical features |
typically affects patients w/ leukemia, lymphoma, organ transplants, etc.
IV drug abuses may inject pure cultures --> cerebral infections, not systemic disease Rhinocerebral zygomycosis |
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Rhinocerebral zygomycosis
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most dramatic of all fungus infections
hyphae of zygomycetes invade large blood vessels and nerves symptoms similar to disseminated aspergillosis: fever, SOB, CP progressive, often lethal |
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Zygomycosis
lab diagnosis |
most cases diagnosed post-mortem
invasion of blood vessels w/ thrombosis --> infarction and necrosis wet mount, ELISA, culture |
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Zygomycosis
treatment |
surgical removal of affected tissue should be attempted
Amphotericin B at greatest dose tolerated |
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Pneumocystic jirovecii
snapshot |
PCP, pneumocystic carinii pneumonia
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Pneumocystic jirovecii
etiology |
Pneumocystis jirovecii
fungal organisms long studied as protistian parasite |
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Pneumocystic jirovecii
epidemiology |
normal human microbiota
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Pneumocystic jirovecii
clinical features |
fever, dry cough, weight loss, night sweats, SOB
DDX: other fungal infections, TB |
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Pneumocystic jirovecii
lab diagnosis |
primarily based on X-ray showing bilateral lower opacity of lungs
sputum ideal clinical sample, but most pts develop unproductive cough sputum --> small round cells without buds, some w/ spherical cells inside |
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Pneumocystic jirovecii
treatment |
NOT react well to antifungal drugs
parasiteic drubs trimethoprima nd sulfamethoxazole in combination with steroids |
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Sings of oppotunistic fungal infections in general:
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FUO
weight loss subcutaneous granulomas disseminated granulomatous disease |
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Aspetate hyphae
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zygomycosis
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Scerotic bodies
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black fungi in chromoblastomycosis
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Single budding yeast cells without capsule
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Blastomycosis
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Septate hyphae
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several opportunistic fungi:
Aspergillosis Phaehyphomycosis etc |
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Spherules with endospores
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Coccidioidomycosis
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Single budding cells with capsule
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Cryptococcosis
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Arthrospores
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Dermatophytes
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Sporangium with endospores
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Rhinosporidiosis
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Intracellular single budding cells
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Histoplasmosis
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Compact mass of hyphae
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sufur grains in eumycetoma
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Spherules without endospores
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adiospiromycosis
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multiple budding cells
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paracoccidiomycosis
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Amphotericin B
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Polyene antibiotic from Streptomyces nodosus
binds to sterols in cell membrane - altering permeability IV administration required |
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common side effects of amphotericin B
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fever, N/V, convulsions
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Flucytosin (5-flurocytosine)
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synthetic (pyrimidine) antifungal
disrupt protein synthesis and distort RNA structure well-absorbed from GI tract Candida and Cryptococcus are resistant |
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side effects of Flucytosin
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leukopenia
thrombocytopenia increase liver enzymes nephrotoxic, hepatoxic |
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Ketoconazole
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imidazole derivative
block membrane sterol synthesis pathway intestinal and topical absorption |
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Ketoconazole side effects
|
vomiting, abnormal liver functions, dry skin,
hypokalemia weakness rash, pruritis |
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Itraconazole
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triazole derivative
for systemic mycoses and superficial infections |
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Itraconazole side effects
|
GI problems
hypokalemia, allergic rash, pruritis |
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Fluconazole
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trizole derivative
oral and IV administration |
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Miconzaole
clotrimazole |
synthetic imidazoles
block membrane sterol synthesis (P-450 dependent step) ergosterol missing from membrane |
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echinocandins
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most recent antifungal drugs
semisynthetic lipopeptides GLUCAN SYNTHESIS INHIBITOR |
