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144 Cards in this Set
- Front
- Back
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How do you get Histoplasma capsulatum? |
Bat or bird droppings |
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Typical exposure history of someone who gets Histoplasma capsulatum |
Recently inside a cave or chicken coop/farm |
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Where is Histoplasma capsulatum located? |
Midwestern and central US along the Mississippi and Ohio River Valley |
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How is Histoplasma capsulatum transmitted? |
Inhaled spores - respiratory |
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What do you see on histology ofHistoplasma capsulatum? |
Macrophages with small intracellular oval bodies |
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How do you diagnose Histoplasma capsulatum? |
Rapid histoplasma urine or serum antigen test |
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Is Histoplasma capsulatum dimorphic? |
Yes - mold in the cold, yeast in the heat |
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What symptoms do most people who get Histoplasma capsulatum have? |
Asymptomatic |
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What do the lungs look like in Histoplasma capsulatum? |
Calcified granulomas with cavitary lesions in upperlobes/calcified nodules with fibrotic scarring, resembling TB |
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What are the symptoms of a localized Histoplasma capsulatum infection? |
1. Pneumonia
2. Erythema nodosum - painful red nodules often on shins |
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What type of person gets disseminated Histoplasma capsulatum? |
Immunocompromised |
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What clinical features are there in disseminated Histoplasma capsulatum? |
hepatosplenomegaly with calcifications (reticuloendothelial system) |
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How do you treat a localized Histoplasma capsulatum infection? |
-conazole drugs |
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How do you treat a systemic Histoplasma capsulatum? |
Amphotericin B |
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Compare size of Histoplasma to RBC |
Much smaller than RBC |
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Where do you find Blastomycosis dermatitidis regionally? |
Great Lakes and the Ohio River Valley + Southeast US |
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Is Blastomycosis dermatitidis dimorphic? |
Yes - mold in the cold, yeast in the heat
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How is Blastomycosis dermatitidis transmitted? |
Inhaled spores |
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Histology of Blastomycosis dermatitidis |
Broad based budding |
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Size of Blastomycosis dermatitidis compared to RBC |
Same size |
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Blastomycosis dermatitidis on Xray |
1. Patchy alveolar infiltrate (haziness) on Xray
2. Lesions or cavities in lungs |
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What patient gets disseminated Blastomycosis dermatitidis? |
Immunocompromised |
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Where does Blastomycosis dermatitidis disseminate to? |
Skin and bone (osteomyelitis) |
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How do you diagnose Blastomycosis dermatitidis? |
Urine antigen test |
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Treatment of localized Blastomycosis dermatitidis? |
-conazoles |
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Treatment of systemic Blastomycosis dermatitidis |
Amphotericin B |
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What region do you find Coccidioidoes immitis? |
1. Southwestern US
2. San Juaquin Valley |
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Route of transmission of Coccidioidoes immitis |
Inhaled spores in dust |
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What increases prevalence of Coccidioidoes immitis infections? |
1. Frequent dust storms
2. Earthquakes |
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What's another name for Coccidioidoes immitis infection? |
San Jauquin Valley Fever |
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Is Coccidioidoes immitis dimorphic? |
Yes, Mold in the cold, but Sphereules filled with endospores in the "heat" (lungs) |
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Size of Coccidioidoes immitis compared to RBC |
Larger than RBC |
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What symptoms do most people with Coccidioidoes immitis have? |
Asymptomativc |
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If people are symptomatic, what is the most usual presentation of Coccidioidoes immitis? |
1. Self-limited acute pneumonia with fever and arthralgias fora couple weeks
2. Erythema nodosum - nodules on shins |
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Imaging of lungs in Coccidioidoes immitis |
Nothing or cavities/nodules in lungs |
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What type of person gets disseminated Coccidioidoes immitis? |
Immunocompromised |
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Where does Coccidioidoes immitis disseminate to? |
1.
Skin 2. Bone 3. Meninges (meningitis) |
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How do you treat localized Coccidioidoes immitis? |
-conazoles |
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Treatment of systemic Coccidioidoes immitis |
Amphotericin B |
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Where do you find regionally Paracoccidioides? |
Brazil and South American |
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Histology of Paracoccidioides in yeast form |
multiple buds that radiate out from a centralvacuole-described as a captain’s wheel |
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Paracoccidioides brasiliensis size compared to RBC |
Larger than RBC |
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Is Paracoccidioides brasiliensis dimorphic? |
Yes, mold in the cold, yeast in the heat |
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How is Paracoccidioides brasiliensis transmitted? |
Respiratory droplets |
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Localized Paracoccidioides brasiliensis infection presents as? |
1. Pneumonia
2. Possible Mucocutaneous lesions in mouth/upper respiratory tract with small hemorrhage |
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Where does Paracoccidioides brasiliensis disseminate to? |
Descending lymphadenopathy starting at the cervical lymph nodes progressing to granulomas in lungs and even inguinal lymph nodes |
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Treatment of mild Paracoccidioides brasiliensis infection |
-conazoles |
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Treatment of severe Paracoccidioides brasiliensis infection |
Amphotericin B |
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What disease is caused by Malasseziafurfur? |
Pityriasis versicolor |
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How is Malassezia furfur diagnosed? |
Spaghetti and meatball appearance on KOH prep of skin scraping |
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Where do you find Malassezia furfur? |
A part of normal skin flora |
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What conditions does Malassezia furfur thrive under? |
generally thrives under hot and humid conditions |
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Pityriasis versicolor 1. Features 2. Mechanism 3. Population affected |
1. hypopigmented/hyperpigmentedpatches on back and chest via:
2. lipid degredation that creates acids thatdamages melanocytes 3. healthy individuals |
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Location of Malassezia furfur infection? |
Stratum corneum of epithelium of skin |
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Does Malassezia furfur disseminate? |
Usually just cutaneous, but possibly could disseminate in immunocompromised |
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What conditions do you see Malasseziafungemia? Symptoms? |
Totalparenteral nutrition (TPN) in neonates can predispose to infection + lipidinfusion through catheter => sepsis and thrombocytopenia |
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Treatment of Malassezia furfur? Mechanism? |
topical Selsun blue (selenium sulfide) => shed stratum cornea |
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What type of fungus causes tinea? |
Dermatophytes |
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What does tinea mean? |
Ringworm |
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Name three dermatophytes |
1. Trichophyton
2. Epidermophyton 3. Microsporum |
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Where do you find dermatophytes? |
Skin |
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Where is tinea capitis? |
Head and scalp |
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Where is tinea corporis? |
Body |
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Where is tinea cruris? |
Groin |
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Where is tinea pedis? What is this called? |
Athlete's foot |
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What type of person gets tinea? |
Athletes |
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What is a common source of dermatophytes? |
Animals and pets |
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What type of lesion is produced in a tinea infection? |
1. Ring
2. Pruritic lesion |
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How do you confirm diagnosis of tinea? |
Hyphae on KOH prep of skin scrapings |
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How do you treat dermatophyte infections? |
Topical -azoles |
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What do you use woods lamps to diagnose? |
Microsporum infection |
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Onychomycosis 1. Define 2. Treatment |
1. dermatophyteof infection of the nail
2. treat with oral terbinafine |
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How do you treat serious dermatophyte infections? Mechanism? Side effects? |
1. oral Griseofulvin for more serious infections
2. deposits in keratin containing tissues 3. Side effect: GI symptoms |
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Where do you find Sporothrix schenckii? |
Treebark, bushes, plants |
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Is Sporothrix schenckii dimorphic? |
Yes, mold in the cold, yeast in the heat |
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Are dermatophytes dimorphic? |
No |
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Is Malassezia furfur dimorphic? |
No |
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Histology of Sporothrix schenckii? |
Branching hyphae |
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What does Sporothrix schenckii look like under microscope? |
Cigarshaped yeast |
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How do you get a Sporothrix schenckii infection? |
Introduced into skin via physical trauma |
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Pathogenesis of Sporothrix schenckii |
localpustule/nodule spreading at initial site of infection which moves in an ascending pattern via lymphatics |
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What is the gold standard way to diagnose Sporothrix schenckii? |
Culture |
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How do you treat Sporothrix schenckii? (2) |
1. Itraconazole or
2. Saturated solution of KI |
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What are the two catalase positive fungi? |
1.
Candida albicans 2. Aspergillus fumigatus |
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Is Candida albicans dimorphic? |
1. Yes, but it is different.
2. Yeast in the cold and mold in the heat. 3. Pseudohyphaesand budding yeast in the cold (20degrees) AND mold germ tubes/hyphaes in the heat (37 degrees) |
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Where do you usually find Candida albicans? |
Normal flora of the GI tract |
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How do baby's present with a Candida albicans infection? |
Diaper rash due to heat and humidity in baby's diaper
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Where does Candida albicans typically present (5)? |
1. Diaper rash
2. Oral candidiasis 3. Esophageal candidiasis 4. Candidal vulvovaginitis 5. Candidal Endocarditis |
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Who gets oral candidiasis? |
1. Immunocompromised
2. Oral steroid users (should be followed with rinsing) |
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How do you diagnose Candida albicans? |
KOH prep of oral scrapings (should be scrapable) |
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Candidalesophagitis 1. What type of patient do you see this and what criteria is necessary 2. Feature |
1. AIDSdefining illness
2. white pseudomembranes 3. CD4 count <= 100 |
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Candidalvulvovaginitis 1. What patient population (3) 2. What pH |
1. Common in diabetes
2. Common post Antibiotics 3. Common in birth control users 4. Does notchange vaginal pH which stays around < 4.0 |
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What type of Candidal infection are IV drug users most susceptible to getting? |
CandidalEndocarditis in tricuspid valve |
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How do you treat a local Candida albicans infection? |
-conazoles |
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How do you treat a severe Candida albicans infection? |
Amphotericin B |
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How do you treat oral candidiasis / candidal esophagitis? |
Nystatin (liquid) |
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What do you use to treat Amphotericin B resistant Candida albicans? |
Capsofungin |
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What temperature do you see budding yeast/pseudohyphaes in Candida albicans? |
20 degrees |
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What temperature do you see mold germ tubes/hyphaes? |
37 degrees |
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Aspergillus flavus 1. Associated with what products? 2. What do they produce? 3. What disease? |
1. Associated with peanuts and grain products
2. Produce aflatoxins which are carinogenic 3. Toxins lead to hepatocellular carcinoma |
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Aspergillus fumigatus histology |
1. Acute angle branching: <45 degrees
2. Septate |
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How is Aspergillus fumigatus acquired? |
Forms conidiophores (stalk) with fruiting bodies => get released and inhaled by humans |
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Allergicbronchopulmonary aspergillosis (ABPA) 1. Pathogenesis 2. At risk population? 3. Symptoms (3) |
1. type 1 hypersensitivity reaction (increased IgE)
2. particularly vulnerable are CF patients 3. wheezing 4. fever 5. migratory pulmonary infilitrate |
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Aspergillomas 1. Define 2. At risk population |
1. solidballs of fungus in the lungs in cavities – gravity dependent
2. peoplesusceptible who already have cavities in lungs like TB or Klebsiella |
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Angioinvasiveaspergillosis 1. At risk population 2. How does it spread in the body? 3. Features (7) |
1. Affects immunocompromised patients (neutropenia most likely, like lymphoma/leukemia)
2. Invades blood vessels => disseminates 3. Fever 4. Cough 5. Hemoptysis 6. Kidney Failure 7. Endocarditis 8. Ring enhancing brain lesions 9. Spread to paranasal sinuses may cause necrosisaround the nose (not the only fungus that has this) |
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How do you treat less severe Aspergillosis? |
1. Voriconazole
2. +Surgical debridement for aspergillomas |
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When do you use Amphoterecin B for Aspergillosis? |
Angioinvasiveaspergillosis |
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What are the four different Aspergillosis infections? |
1. Aspergilus flavus => aflaxatoxin => hepatocellular carcinoma
2. Allergicbronchopulmonary aspergillosis 3. Aspergillomas 4. Angioinvasiveaspergillosis |
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What is the main virulence factor for Cryptococcus neoformans? |
HeavilyEncapsulated made of repeating polysaccharide capsular antigen– antiphagocytic |
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Where do you normally find Cryptococcus neoformans in the environment? |
Soil/pigeon droppings |
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How is Cryptococcus neoformans transmitted? |
Inhaled into lungs |
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Which fungi is urease positive? |
Cryptococcus neoformans |
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What type of patient population does Cryptococcus neoformans infect? |
Immunocompromised like HIV |
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What are the initial symptoms/infection of Cryptococcus neoformans? |
Can be asymptomatic or cough, dyspnea, fever or other serious lunginfections like pneumonia, but will likely not be detected till later =>disseminatesbody |
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What is the most common cause of fungal meningitis? |
Cryptococcus neoformans |
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How is Cryptococcus neoformans diagnosed? |
Bronchopulmonary washings of lung tissue – stained withmucicarmine (red) or methenamine silver stains |
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What type of stain should you use to diagnose Cryptococcus neoformans? |
mucicarmine (red) or methanamine silver stains |
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What is the main fungal disease you would perform a lumbar puncture on? |
Cryptococcus neoformans |
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What would you do with a lumbar puncture of Cryptoccocus neoformoans |
Use Indiaink which outlines Cryptococci capsules as halos (appear whiteish against black ink) |
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Which fungal infection would you diagnose with India ink and how would it appear |
1. Cryptococcous neoformans
2. outlines Cryptococci capsules as halos (appear whiteish against black ink) |
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What serum test would you use to diagnose Cryptococcus neoformans? |
Latex agglutination test detects capsular antigen and causesagglutination |
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How do you treat Cryptococcus neoformans? |
AmphotericinB AND Flucytosine together => followed by maintenance therapy of Fluconazole |
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What fungal family is Rhizopus a part of? |
Mucormycosis |
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What fungal family is Absidia a part of? |
Mucormycosis |
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What are the three fungi a part of the Mucormycosis family? |
1.
Rhizopus 2. Absidia 3. Mucor |
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Who is susceptible to Mucromycosis/Rhizopus? |
Immunocompromised patients are susceptible (leukemia andneutropenia) |
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Where do you find Rhizopus |
bread mold |
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Describe the pathogenesis of Mucormycosis/Rhizopus |
Transmision via spore inhalation => blood vessel walls(proliferates) => invades cribiform plate of skull => brain =>necrosis => black eschar on face and nasal cavities => rhinocerebralmucormycoses and frontal cortex abscess |
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How is Mucormycosis/Rhizopus transmitted? |
Inhaled spores |
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Where does Mucormycosis/Rhizopus proliferate? |
Blood vessel walls |
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What fungal infection invades the cribiform plate? |
Mucormycosis/Rhizopus |
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Major feature of Mucormycosis/Rhizopus infection |
1. black eschar on face and nasal cavities
2. frontal cortex abscess |
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What is the most common predisposing factor to Mucormycosis/Rhizopus infection? |
DKA |
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Histology of Mucormycosis/Rhizopus |
1. Wide angle branching (90 degrees) (cross shaped)
2. Non-septate rods |
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How do you treat Mucormycosis/Rhizopus? |
Surgicaldebridement of dead tissue + Amphotericin B |
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What disease does Pneumocystis jirovecci cause? |
Pneumocystis pneumonia (PCP) |
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What group of patients show symptoms of a Pneumocystis jirovecci infection? |
Immunocompromised show signs of infection vs immunocompetentpeople don’t show symptoms |
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Pneumocystis pneumonia 1. Feature (5) |
1. AIDS defining illness
2. CD4 count <= 200 3. Diffuse interstitial pneumonia (nonproductive cough, noconsolidation) 4. Ground glass appearance bilaterally is possibly seen onxray 5. can also look like crushed ping pong balls |
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What CD4 count do you need to have to be symptomatic with a Pneumocystis pneumonia? |
CD4 <= 200 |
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What CD4 count do you need to have for Candidal esophagitis? |
CD4 <= 100 |
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How do you diagnose Pneumocystis pneumonia? |
1. PCP diagnosis - Bronchoalveolar lavage (BAL) (bronchoscopyprocedure)
2. Methamine silver stain of tissue with disc shaped yeast(ovoid) |
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What type of stain do you use to diagnose Pneumocystis pneumonia and what will you see on stain? |
Methamine silver stain of tissue with disc shaped yeast (ovoid) |
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How do you treat Pneumocystis jirovecci? |
1. Prophylaxis /treatment for CD4 count < 200:
2. Bactrim(Sulfamethoxazole and Trimethoprim are components of Bactrim) 3. Pentamidine can be used for individuals with sulfa allergies– can be used for treatment or prophylaxis |
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What do you use to treat Pneumocystis jirovecci for patients with sulfa allergies |
Pentamidine |
