Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
88 Cards in this Set
- Front
- Back
|
microsporum
|
Dermatophytoses
|
|
|
Trichophyton
|
dermatophytoses
|
|
|
Epidermophyton cloccosum
|
dermatophytoses
|
|
|
Where do dermatophytes live?
|
In the dead skin layer, superficial. Use keratin as a nutrient source.
|
|
|
Tinea Pedis
Tinea Unguim Tinea Cruris |
Athletes foot,
Nail infection, Jock Itch All from dermatophytes |
|
|
Tinea corporis
Tinea Barbae Tinea Capitis Tinea Manum |
Annular (ring) lesions, any part of body, from hugging animals
In beard In head/hair, grows into bulb root On top of hands, no nails all from dermatophytes |
|
|
Onychochysis
|
A dermatophyte infection of the nail, will lose nail, starts to grow into nailbed
|
|
|
How do you get dermatophytes?
|
Cracks in skin, existing lesions, punctures, cuts. Some people are innately resistant to them, they are sensitive to fatty acids of skin.
|
|
|
What is the most common mycoses?
|
Dermatophytes, worldwide occurance, can come from soil, other humans, animals, you name it. Tends to be kind of permanent without treatment.
|
|
|
How do you diagnose dermatophytoses?
|
Direct exam, KOH prep. Look for branched hyphae. Very easy to culture, but slow.
Can do Id rxn - formation of sterile vesicles on hand of hypersensitive person before onset of infection Wood's Lamp is used to ID T. Capits on surface of hair, flouresces under UV light. |
|
|
How do you treat dermatophytoses?
|
Epilation - removal of hair
Tolnaflate - tenactin for skin Griseolfulvin - for nails and hair, systemic Tripehiphen - blocks formation of ergosterol Lamosil |
|
|
This fungus is not dimorphic, has three etiologic agents, and has a worldwide occurence
|
Dermatophytoses - hyphae
|
|
|
This fungus is a subcutaneous mycoses, pigmented, and is dimorphic
|
Sporotrichosis
|
|
|
Sporothrix Schenkii
|
Sporotrichosis
|
|
|
What are the five problems seen in sporotrichosis?
|
1. Lymphocutaneous bubo->ulcer, follows lymph system
2. Fixed cutaneous - doesn't follow lymph system 3. Mucocutaneous - usually do to dissemination 4. Extracutaneous/disseminated - chronic, lesions in bone, periosteum, synovium 5. Pulmonary - Chronic Cavitary Disease - nodular masses with cavities in lungs, fibrosis, pleural effusions, caseous necrosis, leading to death. |
|
|
How do you get sporotrichosis?
|
When skin is torn, such as in a splinter or thorn from roses. It is also called rose gardeners disease. Found in SOIL.
|
|
|
How do you treat sporotrichosis?
|
KI - potassium iodide, it is toxic, must start with low doses, especially if person has hepatosplenic problems.
Amphotercin B if disseminated |
|
|
Where is Rose Gardener's Disease seen?
|
US, Mexico. A hazard to greenhouse workers, anyone working with decaying vegetation (even miners).
|
|
|
What is the parasitic form of sporotrichosis?
|
Yeast. It is pigmented. The infectious form is a black mold (stalk with rosette of spores)
|
|
|
How do you identify sporotrichosis?
|
Direct exam is no good.
Easily cultured on organic material, 37* = dark cigar shaped budding yeast, 25* = black mold. Culture on enriched blood agar. Serology = yeast cell agglutination People may have hypersensitivity rxn to SPOROTRICHIN |
|
|
Malssezia furfur
|
Tinea Pityriasis Versicolor
|
|
|
This superficial mycoses grows on layers of skin and its primary manifestation is to change the pigment color of skin
|
Tinea Pityriasis Versicolor. Mycosis of the stratum corneum, it causes dark spots in winter or light areas that won't tan in the summer. There is little irritation.
|
|
|
How do you treat tinea pityriasis?
|
Keratolytic agents like selson blue, recurrences are common.
|
|
|
How do you diagnose tinea pityriasis?
|
Direct exam with KOH, look for mycelium. It is NOT culturable. Looks like spaghetti and meatballs under microscope.
It is normal flora, prevalent in temperate zones. Found in Iowa, Nevada, can get from foamites. |
|
|
This dimorphic, saphrophytic fungus uses an arthroconidium as its infectious particle.
|
Coccidiodes Immitus - causing coccioidomycosis
|
|
|
This is the most infectious fungus
|
Coccidiodes Immitus
|
|
|
What is the parasitic form of coccidiodes immitus?
|
spherule that produces endospores
|
|
|
How does coccidiodes infect?
|
Inahlde arthroconidia, it gets phagocytized by alveolar macrophages, spore survives and converts to spherule, which releases endospores. Extremely infectious, only need one spore.
|
|
|
What are the two types of infections seen in Valley Fever
|
Coccidiodomycosis has a primary and a secondary infection. 60% asymptomatic.
|
|
|
Describe the primary infection of Valley Fever
|
Primary - fever, malaise, dry cough, anorexia, chest pain, night sweats. Significant weight loss, cachectic. Cutaneous lesions, erythema nodosum, erythema multiforme.
|
|
|
What is erythema nodosum and what disease is it associated with?
|
Anterior tibial itchy raised red nodules, seen in Valley Fever (coccidiodomycosis)
|
|
|
What is erythema multiforme and with what disease is it associated?
|
Lesions above thights, circinate or irregular with raised borders... "target" lesions. Seen in Valley Fever.
Lesions are good, means that it can be controlled. The lesions are generally only seen in caucasian women. |
|
|
Describe secondary pulmonary infection of Valley Fever
|
Disseminated disease. 10% of those with Valley Fever et this. 1/2 have skin lesions, 1/3 meningitis, 1/4 bone lesions. Occurs after an apparent quiescnece of infection, get lesions in skin, bones, joints, organs.
Detected by x-ray. See hemoptysis, cough, chest pain. Cavities may rupture and produce pneumothorax, empyema, or pleural effusions. |
|
|
How do you treat coccidiodomycosis?
|
Supportive therapy if mild
Amphotercin B - only if severe acute, disseminated, pregnant, or theres complicating non-infectious disease Switch to imidazole once getting better (Ketoconazole, fluconazole, itraconazole) |
|
|
Where is Valley Fever found?
|
coccidiodes immitis is found in the American southwest, especially during rainy season. In the lower sonoran life zone. It is MOST SEVERE in dark skinned races. IMmunity is probably life-long.
|
|
|
How do you diagnose coccidiodomycosis?
|
AGAR GEL immunodiffusion is good, 90% or more show positive test by 4 weeks post exposure, the first and simplest test to do
Direct exam of exudates and sputum is beneficial. Isolation is easy, must warn lab. Can only culture saphrophyte, not parasite Serology is diagnostic and prognostic. There is skin testing - coccidioidin or sperulin*, patient will have reaction by time they show symptoms, a good test. |
|
|
This dimorphic fungi is found in the upper mississippi river valley
|
Histoplasmosis - "spelunkers disease"
|
|
|
Histoplasma capsulatum
|
Histoplasmosis (Dibosii in Africa)
|
|
|
What is the infectious and parasitic form of histoplasma?
|
Infectious = microaerulospore, parasitic = yeast, in macrophages
A third form, macroconida, is too big to get into lungs and is used for identification purposes (Tuberculare chlamydospore) |
|
|
Histoplasmosis has what four types of infections?
|
Benign
1. Acute pulmonary histoplasmosis - flu like 2. Chronic cavitary histoplasmosis - mimics cavitary TB, cough, hemoptysis, remission, etc Progressive Disseminated 1. Acute disseminated - NO PULMONARY SYMPTOMS - fever, hepatosplenomegaly, usually involves single organ system - endocarditis, percarditis, meningitis, etc. Ulceration of mucocutaenous tissue (esp. glans) 2. Chronic disseminated - insidious, lifelong, seen in debilitated patients, NO evidence of primary pulmonary infection. Also bone, skin |
|
|
How do you treat histoplasmosis?
|
Amphtericin B for progressive forms, surgery, imidazole
|
|
|
How do you diagnose histoplasmosis?
|
Direct exam - sputum, blood, urine, bone marrow, liver, lymph nodes. Wright or Geimsa stain for small intracellular yeasts = diagnostic.
Serology is diagnostic and prognostic. Does have a skin test - histoplasmin - the earliest positive test, but can cross react with people from california. |
|
|
This fungi is dimorphic, has no asymptomatic form, and males are four times more likely to get it due to greater exposure
|
Blastomycosis
|
|
|
Acquisition of this fungi is from areas covered with bird droppings, bats are carriers too
|
Histoplasmosis
|
|
|
Blastomyces dermatitidis
|
Blastomycosis
|
|
|
A chronic granulomatous and suppurative mycosis that has a primary pulmonary stage frequently disseminated to bone and skin. Can manifest as cutaneous lesions.
|
Blastomycosis
|
|
|
What are the three forms of infection in blastomycosis?
|
1. Pulmonary - mild URT infection, fever, night sweats, anorexia --> massive miliary involvement
2. Cutaneous (exogenous rare, endogenous common), mets, granulomatous ulcer with serpinginous advancing border leaving a depigmented scar 3. Disseminated - skin lesions, oronasal mucosa, respiratory, urogenital, skeletal, CNS, osteomyelitis, periostitis, destructive lesions of vertebrae tibia, femur, meningitis, protsate, testis, epididymis. Untreated mortality 90% |
|
|
What is the infectious and parasitic stages of blastomycosis?
|
Saphrophytic = mold, conidia and hyphae
parasite = yeast, broad based, large size, thick wall not communicable |
|
|
How do you treat blastomycosis?
|
Amphotercin B, imidazole, or 2-OH Stilbamidine
|
|
|
Where is blastomycosis found?
|
SE US, lower mississippi river valley, overlapping with histoplasmosis. Hardest to get, and hardest to have.
|
|
|
How do you diagnose blastomycosis?
|
Direct exam is beneficial - thick wwalle,d broad based connections, single LARGE budding yeast.
Isolation is easy but slow. Hypersensitivity, can be done but not routinely available. |
|
|
This fungus is not dimorphic, it's always a yeast, and it is endogenous to humans
|
Candida albicans - candidiasis
|
|
|
What is a pseudohyphae?
|
A line of yeast
|
|
|
This yeast has two serotypes, A and B, and causes opportunistic infections
|
Candida albicans
|
|
|
What types of opportunistic infections does candidiasis cause?
|
Cutaenous - onychia (nail), paronychia (surrounding tissue. Intertriginous "athletes foot of hand"
Mucocutaneous - thrush, vaginal or oral, can be sexually transmitted Bronchial Pulmonary Meningeal Cystitis and pyelonephritis - Disseminated Can occur anywhere except bone |
|
|
What can cause opportunistic infections of candidiasis?
|
Chronic infections - leukemia, lymphoma, diabetes
Therapy - antibacterial, immunosuppressive, hormonal Physical abuse - fruit pickers, drug addicts, burns, immersion in H2O AIDS |
|
|
How do you treat candidiasis?
|
Systemic - amphtercin, flucytosine or fluconazole, simultaneously
Superficial - nystatin or gentian violet, miconazole Organism is cleared by cell mediated immunity |
|
|
How do you diagnose candidiasis?
|
Direct exam - all fungi gram +, of sputum, CSF, blood, urine, exudates.
Easily cultured with rabbit serum within 3 hours "germ tube formation" Serology seldom used - whole cell yeast agglutination |
|
|
Cryptococcus Neoformans
|
Cryptocoococis
|
|
|
This yeast has a large polysaccharide capsule with four capsular serotypes (A-D) and is NOT dimorphic
|
Cryptococcosis
|
|
|
What are the virulence factors of cryptococcocis?
|
Capsule and phenoloxidase, which converts catecholamines to melanin, important in meningitis.
|
|
|
How do you get cryptococcocis?
|
it grows readily in soil, from BIRD droppings. Associated with pidgeons.
|
|
|
What does cryptococcocis do?
|
Primary pulmonary infection - usually asymptomatic
Secondary infection - to skin, mucus membranes, bone, meningitis (in compromised) THIS IS A MAJOR CAUSE OF DEATH IN AIDS PATIENTS |
|
|
Meningitis in immunocompromised is the major problem with this fungal infection
|
Cryptococcocis
|
|
|
How do you treat cryptococcocis?
|
Amphtercin B with 5-flourocytosine
Fluconazole as prophylaxis for AIDS patients. No drug is 100% reliable. |
|
|
Why is there no vaccine to cryptococcocis?
|
Body does not produce antibody to it.
|
|
|
How do you diagnose cryptococcosis?
|
Direct Exam with India Ink for capsule, use CSF as best specimen
Easily cultured, colonies aren't round Serology - look for latex particle agglutinin |
|
|
Aspergillus Fumigatus, Aspergillus Flavus, Apergillus Glaucus, Nidulans, Niger
|
Aspergillosis
|
|
|
This fungus is not dimorphic, it is a mold both inside and outside of host. Its infectious particle is a conidium spore.
|
Apsergillosis
|
|
|
This fungus has a cell wall associated endotoxin - aflatoxin, which is released in decomposition of grains
|
A. Flavus, aspergillosis.
|
|
|
Aspergillosis gives off what 5 types of infection?
|
Pulmonary - with mucopurulent blood tinged sputum due to cavitary hemoptysis. Also can get large fungus ball in lung.
Mycetoma - subcutaneous fungal swelling Endopthalmitis - clouding of anterior chamber of eye, Hypopyon Otomycosis - ear infection, swimmers ear. Digests cerumin and releases metabolites that irritate ear. Allergy Also an opportunistic pathogen. |
|
|
What is an aspergilloma?
|
A pulmonary fungus ball caused by Aspergillosis.
|
|
|
How do you treat aspergillosis?
|
Amphotercin B
Fungus ball resection Asthma desensitization Disseminated = no cure |
|
|
How do you get aspergillosis?
|
Inhale it, it's soil born. Particularly prevalent in people with WBC disorders.
|
|
|
What is the infectious and parasitic forms of aspergillosis?
|
Septate branching hyphae (mold)
|
|
|
How do you diagnose aspergillosis?
|
Direct exam is not distinctive for spergilli,
Isolation is easy serology is not routine Endotoxin will turn limulus assay positive (horse shoe crab) |
|
|
Rhizopus (black bread mold)
|
Zygomycosis (mucormycosis)
|
|
|
Mucor
|
Mucormycosis (zygomycosis)
|
|
|
Absidia
|
Zygomycosis (mucormycosis)
|
|
|
This true fungi is an extremely rapid grower that is aseptate and its infectious particle is a sporangiospore
|
Mucormycosis (zygomycosis)
|
|
|
This fungus is not dimorphic and likes to affect rhinocerebral and thoracic tissues
|
Mucormycosis (zygomycosis)
|
|
|
What are the two types of infection brought on by mucormycosis?
|
1. Rhinocerebral - in acidotic diabetics, it infects sinuses and goes to eye and brain, patients become comatose
2. Thoracic - leukemics or those with lymphomas, get pneumonia, hemoptysis, massive cavitation, pleural friction rub |
|
|
This fungus has a predilection for arteries and vessels, unconfined areas, causing infarction and necrosis of tissues.
|
Mucormycosis. It is the fastest growing fungi.
|
|
|
How do you treat mucormycosis?
|
Amphotercin B, CORRECT UNDERLYING DISEASE (most important, ie diabetes, leukemia)
|
|
|
Where do you find mucormycosis?
|
Soil
|
|
|
Patients on dialysis have a problem with this fungus because they take deserol due to their high free iron
|
Mucormycosis
|
|
|
How do you diagnose mucormycosis?
|
Direct exam for coencytic hyphae, which grows incredibly fast. It has hyphae that are 2-3x larger than other fungi. Occludes vessels easily. Get it from sputum and other exudates.
|
|
|
What is the infectious and parasitic particle of mucormycosis (zygomycosis)?
|
Infectious = sporangiospore, parasite= aseptate hyphae
|
