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79 Cards in this Set
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- Back
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what are the cutaneous mycoses |
dermatophytes- fungus that invades keratin of skin hari and nails
ringworm, onychomycoses |
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keratinase is made by who
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dermatophytes, this enables them to inhabit keratinized areas
**dermatophytes are a group of fungi that invade the keratin of skin, hair and nails |
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what are the 3 main categories of dermatophytes? what are the otehr forms
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1. Microsporum: M canis
2. Trichophyton: T rubrum, T tonsurans, T mentagrophytes 3. Epidermophyton: E floccosum **Microsporum and trichophyton are in the Arthrodema family **other cutaneous forms are: candica albicans, Malassezia and horteae |
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what property of skin allows microsporum, trichphyton, epidermophyton, malassezia and hortaea to grow
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moist skin
these dermatophytes have keratinase which allows them to live in keratinized areas like the skin |
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tinea is what
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ring worm
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where is the ring worm (tinea)
1. T barbae 2. T capitis 3. T corporis 4. T cruris 5. T manus 6. T pedis 7. T unguium |
1. barbae- beard
2. capitis- scalp, common in kids 3. corporis- torso 4. curis- groin 5. manus- hand 6. pedis- foot, common in US adults 7. unguium- nail, common in males (shoes/boots) tinea is RINGWORM |
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where does the hyphea and arthrocondida grow in a dermatophyte
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dead keratinized tissue
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where is the best place to get sample for dx of ring worm (tinea) and onychmycoses? what do you culture the fungus on
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under the nail
*sabouraud agar or Dermatophyte Test Medium (DMT) **grown at room temp, 1-4 weeks, early detection get red color change in 3 days on DMT |
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what might you be trying to grow at room temp on sabouraud agar or DTM, takes 1-4 weeks. sample from under nails
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onchomycoses
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what allows early detection of dermatophyte growth?
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usually grown on sabouraud agar 1-4 weeks
if grown on DTM- dermatophyte test medium can get phenol red in 3 days |
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what is the infective adn dx stage of onchycomycoses
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arthrocondidium (artherospore)
**person to person, fomite transmission, these spores survive in the environment |
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what is teh micro and macrocondidium
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asexual spores seen in culture of dermatophyte infection. not seen in lesion
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ok so arthrocondidia are the dx and infective stage for dermatophyte infections, how are they visualized
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10% KOH or lactophenol cotton blue
**find arthrocondidia and hyphea in tissue (hair, skin, nails) |
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what might you see if you look at dermatophyte slide mounted in KOH
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hyphea and arthroconidia
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what is trichophytin
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crude AG of dermatophytes
the carb part--> immediate response the protein part --> delayed response |
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with trichophytin what causes immediate and delayed response, who is more likely to have chronic infection
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trichophytin is the crude AG of dermatophytes
Carbs --> immediate Peptide --> delayed chronic: pt with immediate (carb) or w/o delated (protein) |
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what is the AG of dermatophytes
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trichophytin
carb--> immediate repsonse protein --> delayed response a person who gets the immediate and NO delayed is at greater risk for chronic infectino |
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what is the dermatophyte
1. zoophilic 2. Anthrophophilic 3. Geophilic |
1. zoophilic- animal transmitted to ppl
2. anthrophophilic- human transmission 3. geophilic- from soil to ppl **invade non viable keratinized tissue |
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where do dermatophyes invade
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invade nonviable keratinized tissue
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what is the keratinophilic fungus that infects skin, hair, nails . are teh infections superficial or deep
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dermatophytes
superficual |
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where are these common
tinea capitis- tinea pedis tinea unguium |
capitis- kids (scalp)
pedis- adults in us (feet) unguium- men (shoes boots) nail |
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dermatophyte
where on body where in world infections |
moist areas
world wide but more common in tropical **arthrospores: infective spores and fragmented hyphal elements, other infective spores (sexual and asexual exist) arthrocondidia **lesion are inflammed at edge w/central clearing, hair loss, itchy, disseminates in HIV pts |
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what do dermatophyte infections look like
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lesion inflammed at edge, central clearing, hair loss, itchy, not debilitating, disseminate in pts with HIV pts
grow in hair, nails, outer skin |
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if you see an infection in areas with keratin (skin, hair nail) that is red at edge and central clearing zone. what is it
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dermatophyte
can cause hair loss |
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what puts you at risk for dermatophyte infection
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hot tubs
HIV cushings- increased cortisol affects inflammatory response athletics- wrestling, karate **nail trauma, DM, |
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what are the 1 and 2 most common dermatophyte infections in humans
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1. t rubrum
2. t mentagrophytes **tinea barbae, affects hair and skin of beard and neck: erythema, scaling, pustules, highly inflammatory! |
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what is dermatophytid
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-id reaction
dermal reaction to fungal agents, hypersentitivity at distal sites, lesions devoid of organism, most common in tinea pedia, sometimes result of excessive treatment **inflammatory response associated with athletes foot |
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what are the antifungal agents, what do they target
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target: ergosterol in cell membrane, kinds toxic to human cells
amphotericin A, nystatin, ketoconazole, clotrimazole, terminafine |
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what is lamisil (terbinafine)
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antifungal used in dermatophyte infection
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what are some good tx for dermatophytes
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1. azoles
2. benzalkonium chloride 3. undecylenic acid (fatty acid) **laser treatment, remove nail |
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what is benzalkonium used for? what else can be used
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dermatophyte- onychomycosis
can also use undecyclenic acid- OTC fatty acid |
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antifungal agents that interfere with fungal sterol synthesis include__________
and systemic antifungal drugs__________ and ______ interferes with microtubule function and mitosis; laser therapy and surgical avulsion of affected toenail are other options. |
azole creams (eg, miconazole, tolnaftate, clotrimazole)
(eg, terbinafine, griseofulvin, itraconazole), griseofulvin |
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undecyclenic acid, OTC Fatty acid
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what are some practicle ways to prevent dermatophyte infections
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hygeine
keep skin dry dont share clothes/towels fungicidal soap, tea tree oil sandles rather than barefoot **spores (arthrocondidia) are viable in shed skin and hair, vacuum lots! |
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what can kill dermatophyte spore
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benzalkonium chloride
chlorine bleach detergents |
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tell me about t barbae
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t rubrum, T verrucosum
inflammed lesion in beard/neck. red, scaling, pustule. highly inflammatory |
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tell me about tinea capitis
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microsporum canis, trichophyton mentagrophytes, t tonsurans
**child hood disease that resolves spontaneously at puberty **infection of hair and scalp- some make black dot ringworm. infected hairs break off- alopecia. can get boggy inflammation |
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what is the dermatophyte infection that is common in childhood but respolves at puberty
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tinea capitis (M canis, trichophyton mentagrophytes, T tonsurans)
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what is the most common pediatric dermatophyte infection world wide
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tinea capitis
infection of hair/scalp some make black dot ringworm infected hairs break off at follicle- alopecia, can be perm treat sytemically Trichophyton (endothrix or ectothrix); Microsporum (ectothrix) |
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what us an endothrix and ectothrix infection with tinea capitis
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Endo: fungus IN the hair, trichophyton
Ecto: ON the hair shaft, trichophyton, microsporum |
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trichophyton mentagrophytes causes what
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tinea capitis, ringworm of the hair
also caused by: trichophyton verrucosum **can be flourscent stain |
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tell me about microsporum canis
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causes tinea capitis,
alopecia with kerion macrocondidia, microcondidia mycelium after several days **zoonitic: adult cats are carriers, kittens/puppies are symptomatic |
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what is teh DOC for tinea capitis
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griseofulvin, itraconazole, terbinafine, fluconazole
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what is tinea corporis
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annular scaly plaques and vesicles
microsporum canis, trichophyton rubrum T mentagrophytes **candida makes similiar lesion |
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whats jock itch
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tinea cruris, SUPER itchy
**epidermaophyton floccsum, trichophyton rubarum, T mentagrophytes |
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what makes tinea cruris grow more
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scrotum is warm and moist
this is jock itch |
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what predisposes tinea cruris (jock itch)
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DM
obesity sweat towels, bedding, clothes etc |
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what kind of conidia is associated with trichophyton mentagrophytes
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microcondidia
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whats tinea manus
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dermatophyte that infects palms/fingers// usually one hand is affected. assoicated with tinea pedia
scaling and erythema **trichophutoin rubrum, t mentagrophytes |
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whats a fingal infection of the hand called
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tinea manus
usually only one hand is affected |
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what causes athletes foot (3)
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1. epidermophyton floccosum
2. trichophyton rubrum **most common 3. t mentagrophytes **tinea pedis |
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what is the most common cause of athletes foot (tinea pedis)
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T rubrum
**peeling and cracking foot, linked to shoe use, most prevalent dermatophytosis **can get really nasty: toes, web, scaling, weythema, vesicles, puritis |
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whats tinea unhuium
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onychomycoses, common in adults. nail fungal infection
epidermophyton floccusum Trichophyton rubrum t mentagrophytes *also candida- yeast, not fungus |
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what is the treatment for tinea unguium
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needs systemic AB, topical is limited use
**nails get thick and discolored. common in adults *common T rubrum **conidia |
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tinea unguium can be mistaken for what
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psoriasis
scabies |
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what is tinea verssicolor
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a distractor
malassezia furfur aka pityriasus vesicolor |
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malassezia furfur is what
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unbranched hyphae, spherical cells
yeast like colony depigmented macule lipophilic GF world wide, common in young adults tx iwth selenium or miconazole *hypopigment **this is tinea versicolor, (a distractor) |
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what causes hypopigmented sun spots
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malassezia furfur, tinea versicolor
treat with topical, miconazole, or selsum |
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what is hortawa weneckii (tinea nigra)
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superficial fungus that causes black/brown lesion on palm and feet
painless seen in tropical areas ID with KOH tx with iodine/azole cream |
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what is the brown fungal skin lesion
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tinea nigra (hortaea werneckii)
**brown skin lesions, seen in tropics. common in young females **common on palms **can see septate hyphea with KOH prep **tx with iodine and azole cream |
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A man presents with a pruritic rash on the
thigh. A skin scraping cleared in 10% KOH reveals fungal elements. The most likely elements to be seen microscopically are: 1 Yeast cells w/ germ tubes 2 Sporangiospores 3 Microconidia 4 Macroconidia 5 Arthroconidia |
**arthroconidia, this is the infective stage
**jock itch- tinea curis |
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A child presents with a bald spot on the scalp.
The lesion fluoresces bright green w/ a Wood’s light. The mother indicates that her daughter sleeps w/ a cat. What is the most likely agent? 1 Candida 2 Histoplasma 3 Microsporum 4 Cryptococcus 5 Malassezia |
microsporum canis
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what are 4 genre of subcutaneous mycoses
where are they found |
pseudoallescheria
fusarium madurella sporothrix **dimorphic fungi, crease chronic infections *found in environment (decaying vegetation) **traumatic inoculation **insidious disease **limited therapies |
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what is the type of disease that is a fungus, chronic infection, found in decaying vegetation and causes disease from traumatic inoculation, insidious onset
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subcutaneous mycoses
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whats sporotrichosis, sporpthrix schenckii
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subcutaneous mycoses
**know this one **fungus found in environment and gets traumatic inoculation (thorn, splinter) etc, chronic disease, insidious onset |
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what are the characteristics of the subcutaneous infection, sporothric schenckii
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thermally dimorphic
looks like flower chronic granulomas and necrosis. causes streaks from point o finoculation on DOC: amphotericin B or itraconazole **traumatic inoculation- develops as abcess, nodule, uilcer along lymphatics |
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what is the self limited mycoses that forms as abcess, nodule, ulcer that occurs along lymphatic lines
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subcutaneous mycoses
sporothrix, dimorphic. traumatic inoculation |
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what causes lumphocutaneous sporotrichosis
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its the nasty nodular, ulcerative lesions associated with lymphatics. caused by sporothrix schenckii
traumatic inoculation- thorns, decaying wood common in gardeners *world wide disease |
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what disease is assoicated with gardeners/envirnment with thorns and things
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Sporothrix schenckii
Lymphocutaneous Sporotrichosis, ulcers along lymphatics |
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what is the dx of Sporothrix schenckii
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specimines have pus,
yeast is not often found clusters of conidia on sabouraud agar |
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whats maduromycosis
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its a medical curiosity (madurella mycelomatis, M grisea)
**its called Mycetoma: eumycetoma, maduromycosis, madura foot- chronic infection refractory to treatment |
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madura foot, mycetoma
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chronic infection refractory to treatment
**multiple draining sinus, granules in sinises are really microcolonies, localized in subcut tissue, fascia, bones |
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tell me about mycetoma
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its caused by multiple draining sinus, granules in sinus are really microcolonies
localized to subcut tissue, fascia or bones common in tropical areas like africa, hard to treat |
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in what disease do Sinuses contain granules or microcolonies of the fungi
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madurella
mycetoma **hard to treat |
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what is actinomycetoma
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gram +
wounds, mouth, intestinal tract, lungs chronic and granulomatous lesion contributes to dental disease tx with penicillin |
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Pseudallescheriasis, what is this
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commonest mycetoms in US, also in latin america, white grain mycetoma
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which mycotemes is common in US
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Pseudallescheriasis
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tell me about fusarium
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subcutaneous mycometes
**mycetoma, opprotunistic agent, tropical disease **isolated from draining sinus tract or biopsy, Hyphae visible with KOH |
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whats the tx for eumycotic mycetoma
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doset respond to chemo
use azoles to slow disease course amputation si too radical |
