TB Flashcards
What does it mean that myobacteria are acid fast?
They hold fast to the rain stain and resist the acid alcohol from decoloring them
3 features to remember about myobacteria Tb?
Aerobic, acid fast, non motile
What is the hallmark histo of TB?
Caseous necrosis
What does a positive PPD skin test mean?
Exposed or infected at some point in time
So basically, what 3 types of people can have a positive test?
Active, latent, or cured
What is the reason for a false positive and a false negative?
someone who has had the BCG vaccine
Someone who is anergic
Essentially, what is going on with primary and secondary/reactivation TB>
Primary is usually an asymptomatic lung infection. Immune system walls off the bacteria and they lay dormant and can infect against, hence secondary .
Essentially, what is causing the dormant stage of the pathogens?
The body walls off the TB in the caseous granulomas then they heal with fibrosis and calcification. Some TB are still viable in there.
Explain a Ghon Foci and a Ghon complex?
The calcified granulomas is a Ghon foci. When there is a Ghon foci along with a calcified perihilar lymph node, then we have the Ghon complex.
When there is a symptom with primary TB, what are the most common symptoms and where is the lung do we usually have TB primarily?
Middle and lower lobes.
Low grade fever and cough
When do we see symptomatic primary TB, what 3 patient types?
Kids, elderly and immunocompromised
What do we see on CXR for symptomatic TB?
Hilar LAD and middle and lower lobe infiltrates
What can the TB develop that we can also see on CXR?
Pleural effusions
What happens when the primary infection is not contained?
Then it becomes primary progressive TB
What are the three types of primary progressive?
Caseous, bronchopneumonia, and miliary TB.
Where is the most common site of reactivation TB and how does it present?
Lungs.
Apical areas of the lungs causing cavitation.
What two cells are causing the cavitations and why?
T cells and macrophages are trying to wall off the bacteria, so they are basically killing the lung tissue.
4 symptoms of secondary TB?
Fever, night sweats, weight loss, and productive cough.
Basically, what is going on when the PPD is injected?
There will be a reaction if there was a previous exposure
What type of hypersensitivity reaction is PPD?
Type 4, which is delayed type
What is the other confirmatory stain for TB along with zeel neelsen?
Kinyon
What do we call TB strains that are resistant to INH and Rifampin or have a positive NAAT R test?
Multi drug resistant
What is our first step in management of a patient with TB along with the 4 first line drugs?
Isolation room under negative pressure
What is another name for b6?
Pyridoxine
