Tuberculosis - clinical approach

Question 1

Host risk factors for TB (5)

Answer 1

1. weakened immune system
2. substance abuse
3. systemic diz
4. age
5. males

Question 2

Environmental risk factors for TB

Answer 2

1. household contacts
2. minority/3rd world country

(alot of people living in small spaces)

Question 3

MC symptoms of TB

Answer 3

1. fever
2. coughing > 3 weeks (MC pulm sx)

Question 4

2 major patterns of tb diz

Answer 4

1. primary tb (primary progressive)
2. secondary tb (post primary)

secondary = reactivation (95% of cases)

Question 5

Primary tb ghon focus is found where in the lungs? Where is secondary tb found in the lungs?

Answer 5

• lower lobes
• upper lobes

Question 6

progressive primary disease (tb)

Answer 6

pneumonia that may progress to disseminated TB

Question 7

In the absence of HIV > 80% of cases only involve ________.

Answer 7

the lungs

Question 8

consumption

Answer 8

ongoing smoldering tb from lack of treatment

chronic and debilitating

Question 9

greater than 25% of TB cases have spread to the ______

Answer 9

lymph nodes

Question 10

miliary TB

Answer 10

hematogenous spread of tb (primary or secondary)

immune compromised and children

Question 11

What are the differences of primary vs. secondary TB on CXR?

Answer 11

• primary: dense, homogenous parenchymal consolidation
• secondary: ill-defined patchy consolidation, clustered parenchymal opacifications

Question 11

Ranke complex

Answer 11

fibrosis & calcification of Ghon’s complex

Question 12

Answer 12

lymphadenopathy
lower lobe consolidation??

Question 13

How to establish definitive dx (3)

Answer 13

1. bronchoaveolar lavage or bx –> culture
2. AFB smear (acid-fast bacilli)
3. NAAT (PCR)

Question 14

Best INITIAL test for tb dx

Answer 14

CXR

Question 15

Most sensitive test to dx tb

Answer 15

biopsy

Question 16

When is PPD (aka Mantoux) used for tb assessment?

purified protein derivative

Answer 16

screening

(do NOT use for acute)

Question 17

First line tx for active tb

Answer 17

1. rifampin
2. isoniazid
3. ethambutol
4. pyrazinamide

RIPE

Question 18

CDC guidelines for tx active TB

Answer 18

• 2 months intensive/daily dosing (RIPE)
• 4 months continuation phase/3 times/week (INH, RIF)

Question 19

Length of tx for latent tb

Answer 19

3 months: INH, RIF

Question 20

Latent TB has negative

Answer 20

1. sputum
2. CXR

Question 21

Which TB med causes liver failure, neuropathy, B6 deficiency and lupus-like rxn

Answer 21

INH

Question 22

Which TB medication causes orange/red bodily fluids

Answer 22

rifampin

Question 23

positive PPD or mantoux test

Answer 23

> 15 mm wheal (raised area)
10 mm if drug user, immigrent, child < 4, exposure
5 mm if HIV, fibrosis on CXR, organ recipient

pos PPD, but no other symptoms = latent; they may have cleared it

Question 24

Fastest results for TB

Answer 24

1. Quantiferon 1. T-SPOT | ??????

Question 25

TB prevention

Answer 25

1. bacillus calmette-guerin (BCG vax) 1. treatment for all latent TB | 50% effective, less w/age, but effective w/children

Question 26

Who is BCG vaccine given to (2)?

Answer 26

1. children 1. healthcare workers