Tuberculosis - clinical approach Flashcards
Host risk factors for TB (5)
- weakened immune system
- substance abuse
- systemic diz
- age
- males
Environmental risk factors for TB
- household contacts
- minority/3rd world country
(alot of people living in small spaces)
MC symptoms of TB
- fever
- coughing > 3 weeks (MC pulm sx)
2 major patterns of tb diz
- primary tb (primary progressive)
- secondary tb (post primary)
secondary = reactivation (95% of cases)
Primary tb ghon focus is found where in the lungs? Where is secondary tb found in the lungs?
- lower lobes
- upper lobes
progressive primary disease (tb)
pneumonia that may progress to disseminated TB
In the absence of HIV > 80% of cases only involve ________.
the lungs
consumption
ongoing smoldering tb from lack of treatment
chronic and debilitating
greater than 25% of TB cases have spread to the ______
lymph nodes
miliary TB
hematogenous spread of tb (primary or secondary)
immune compromised and children
What are the differences of primary vs. secondary TB on CXR?
- primary: dense, homogenous parenchymal consolidation
- secondary: ill-defined patchy consolidation, clustered parenchymal opacifications
Ranke complex
fibrosis & calcification of Ghon’s complex
lymphadenopathy
lower lobe consolidation??
How to establish definitive dx (3)
- bronchoaveolar lavage or bx –> culture
- AFB smear (acid-fast bacilli)
- NAAT (PCR)
Best INITIAL test for tb dx
CXR
When is PPD (aka Mantoux) used for tb assessment?
purified protein derivative
screening
(do NOT use for acute)
positive PPD or mantoux test
> 15 mm wheal (raised area)
10 mm if drug user, immigrent, child < 4, exposure
5 mm if HIV, fibrosis on CXR, organ recipient
