Fungal Infections of the Respiratory Tract Flashcards
What is the most common endemic fungal infection in the US?
Histoplasmosis
Where is histoplasma usually found?
Midwest and central states along the ohio and Mississippi river valleys
What type of soil is histoplasmosis usually found in?
Those with bird or bat droppings
Spelunkers disease = ?
Histoplasmosis
What is the morphological change that histoplasma undergoes from the soil to in the body?
Yeast in the heat, mold in the cold
What are the typical locations that contain histoplasmosis? (3)
Caves
Farm buildings
Wood lots
What are the two major routes through which histoplasmosis gains access to the body?
Inhalation
Transplantation
Who is at risk for the development of histoplasmosis?
Impaired cell mediated immunity
What are the findings with resolved histoplasmosis infections?
Calcified lung nodules
What is the mortality rate with histoplasmosis?
7.5%
What is the most common manifestation of histoplasmosis?
Asymptomatic infection
How long do subacute cases of histoplasmosis last for?
Weeks to months post exposure
What are the ssx of histoplasmosis?
Fevers Chills Cough Chest pain Myalgias
(non-specific)
What are the usual exam findings with histoplasmosis?
Rales and possibly consolidation
What are the CXR finding with histoplasmosis?
Hilar and mediastinal lymphadenopathy with focal infiltrates which are patchy or nodular in appearance
Cavitations with histoplasmosis, but are sometimes seen with what disease?
COPD
How long does the LAD with histoplasmosis last for?
Years
What is the main other noninfectious disease that looks very similar to histoplasmosis?
Sarcoidosis
What is sarcoidosis?
Decreased cell mediated immunity, but increase humoral immunity. This causes
Who is sarcoidosis usually seen in (Ethnicity)?
Blacks
What are the two forms of acute histoplasmosis?
Reticulonodular
Milliary
What are the pulmonary clinical manifestations of histoplasmosis? (3)
Broncholithiasis
Mediastinal granuloma
Fibrosing mediastinitis
What are the cardiac/vascular clinical manifestations of histoplasmosis? (2)
Pericarditis
Superior vena cava syndrome
What are the systemic clinical manifestations of histoplasmosis? (1)
Rheumatological
What are the dermatological clinical manifestations of histoplasmosis? (2)
Erythema nodosum
Erythema multiforme
What is erythema nodosum?
an inflammatory condition characterised by inflammation of the fat cells under the skin, resulting in tender red nodules or lumps that are usually seen on both shins. It can be caused by a variety of conditions
What pulmonary findings what suggest histoplasmosis? (4)
- Pneumonia with mediastinal adenopathy
- Mediastinal or hilar masses
- Pulmonary nodule
- Cavitary lung disease
What other finding with pericarditis should histoplasmosis be suspected?
-Pericarditis with LAD
What is the most useful test to diagnose Histoplasmosis? How long does this take?
Cultures
Weeks
What is the fastest way to diagnose histoplasmosis?
Antigen detection in the blood or urine
What does the urine/blood test for histoplasmosis look for?
H. Capsulatum galactomannan
Complement tities of what value are highly suggestive of histoplasmosis?
1:32
Which has a higher sensitivity, and which has a higher specificity: complement fixation, immunodiffusion
CF = sensitive ID = specific
How do you treat mild-moderate Histoplasmosis?
Itraconazole for 6-12 weeks
How do you treat moderate-severe Histoplasmosis?
Amp B 1-2 weeks, then itraconazole for 12 weeks
How do you treat the cavitary form of histoplasmosis?
Itraconazole for at least 12 months
What is the most common region of the US for coccidioidomycosis?
Desert southwest
What are the 2 specific of coccidioidomycosis? Where are each of these found?
Immitis = california
Posadasii =elsewhere
What form is coccidioidomycosis found in?
Yeast in the heat, mold in the cold
What is the seasonal variation with coccidioidomycosis?
dry seasons following rainy ones
Valley fever = ?
coccidioidomycosis
What is the histological finding with coccidioidomycosis?
Spherules
Spherules on histology = ?
coccidioidomycosis
What is the most common clinical presentation of coccidioidomycosis?
Asymptomatic to benign fever
What is the most common symptom of coccidioidomycosis?
Pneumonia with hemoptysis
Fatigue and arthralgias
What are the skin lesions that can be found with coccidioidomycosis? HOw common is this compared to Histoplasmosis?
Erythema multiforme
Erythema nodosum
Much less common than histo
What is the treatment for the pulmonary nodules that can occur with coccidioidomycosis?
None needed
Which 2 forms of pneumonia d/t coccidioidomycosis infection requires treatment?
Reticulonodular
Chronic fibrocavitary pneumonia
What is the best way to diagnose coccidioidomycosis? Why?
Serological testing
Culture takes too long to grow, and exposes lab workers
True or false: any positive test for coccidioidomycosis is significant
True
Does a negative test for coccidioidomycosis r/o it definitively?
No
What are the specific serological tests for coccidioidomycosis?
ELISA
Complement fixation
How do you determine if the cavitary lesions seen with coccidioidomycosis need treatment?
If cavities are thin walled and asymptomatic
What is the use of the skin test for coccidioidomycosis?
helps to r/o, but any exposure will result in a positive test
What is the treatment for chronic fibrocavitary disease caused by coccidioidomycosis?
12 months of an azole
What is the treatment for reticulonodular pneumonia caused by coccidioidomycosis?
Amp B
Where, geographically, is Blastomycosis usually found?
Southeastern and south-central states
Where in the environment is Blastomycosis usually found
WOoded areas with decaying vegetation
What is the form of blastomycosis in the environment and in the body
Yeast in the heat, mold in the cold
What are the histological findings of Blastomycosis?
Broad based budding yeast with a thick wall
What are the two most common infections with Blastomycosis?
Lung (91%)
Skin (18%)
What are the characteristics of the skin lesion produced by Blastomycosis?
Verrucous with irregular borders and gray to violet color
What is the usual presentation of Blastomycosis (when symptomatic)?
Pneumonia (just like TB/others)
What are the characteristics of the cough with Blastomycosis ?
non-productive, progressing to productive
How do you diagnose Blastomycosis?
Culture is definitive, but presumptive diagnosis can be made with sputum sample with yeast
True or false: symptomatic Blastomycosis usually requires treatment
True
What is the treatment for Blastomycosis?
Amp B until 1-2 weeks
If mild, then itraconazole
Who gets infected with pneumocystis?
Only Immunocompromised
True or false: most of us never encounter pneumocystis
False–very common. Is a opportunistic infection
What type of tumors predisposed to pneumocystis infection?
Solid tumors or hematological malignancies
What is the usual presentation of pneumocystis infection in the HIV patient? Non HIv?
- HIV = gradual
- Non-HIV = fulminant respiratory failure
What are the typical ssx of pneumocystis infection?
Cough and fever
What are the CXR findings with pneumocystis?
Bilateral interstitial infiltrates, maybe pneumothorax
What are the CT findings with pneumocystis?
Ground glass changes
HIV patient who develops pneumonia leading to a pneumothorax should be suspected of having what infection?
pneumocystis
Can you culture pneumocystis? How do you diagnose it?
- No
- Need to stain with special stains
What is the typical way to diagnose pneumocystis?
Hypertonic saline and BAL sample
What is the treatment for pneumocystis?
TMP-SMX
What level of prednisone use should prophylaxis begin for pneumocystis?
Greater than than 20 mg daily
Use of what drug indicates that need to use prophylactic therapy for pneumocystis?
Alemtuzumab
What leukemia should have prophylaxis for pneumocystis?
ALL
What is the prophylactic treatment for pneumocystis?
TMP-SMX once daily
Below what CD count are HIV patients susceptible to pneumocystis?
200
