#23- chronic pneumonias

Question 1

What do fungal and mycobacterial pneumonias have in common?

Answer 1

• symptoms
• pathophysiology: they are both intracellular pathogens of macrophages!
• both have upper lung involvement.
• both require inhalation of 2-5 um particles.
• histopathology: both have granulomas!
• high index of suspicion is required, diagnosis often delayed.

Question 2

what are the symptoms of mycobacterial and funcal pneumonias?

Answer 2

• fatigue
• wt loss
• fever
• cough
• dyspnea

Question 3

4 drugs that make up the first line treatment for Tuberculosis

Answer 3

For 6 months
isoniazid
rifampin
For first 2 months
-pyrazinamide
-ethambutol

Question 4

How is TB transmitted?

Answer 4

person to person only, it is a human-only disease!!

Question 5

How is latent tuberculosis diagnosed?

Answer 5

tuberculin skin test or IGRA (blood test)

along with a negative Xray.

Question 6

how is active TB diagnosed?

Answer 6

Sputum acid fast smear, and culture.

Question 7

Treatment for active TB vs. latent TB

Answer 7

6 months of treatment for active, 9 months for latent.

Question 8

Case: weight loss, fevers, cough, no response to antibiotics. He cleaned out a pigeon infested attic 3 months ago. Diagnosis/

Answer 8

Histoplasmosis.

Question 9

CXR findings in acute Histoplasmosis

Answer 9

localized pulmonary infiltrate + adjacent hilar adenopathy.

Note: this is also seen in tuberculosis, lung cancer, and sarcoid.

Question 10

Describe the pathogenesiss/ transmission of histoplasmosis.

Answer 10

microconidia are inhaled, incubate in the lung for 2 weeks, convert to yeast, then yeast are engulfed by macrophages.

Question 11

What predisposes to chronic histoplasmosis?

Answer 11

pre-existing lung disease (eg, COPD)

Question 12

What predisposes to disseminated (progressive) histoplasmosis?

Answer 12

immunosuppression, especially anti-TNF therapy!

Question 13

If someone has a fever, and is on anti-TNF therapy, what disease should you be thinking?

Answer 13

disseminated histoplasmosis (TNF is essential to immune defense against histo.

Question 14

Someone is immunocompromised, comes in with a fever. what should be on your differential ?

Answer 14

histoplasmosis.

Question 15

if you think a patient has sarcoid, you need to rule out ___

Answer 15

histoplasmosis and TB

Question 16

When is histoplasmosis urine antigen a good diagnostic test?

Answer 16

for Severe cases! disseminated disease, and for diffuse acute histoplasmosis. not good for others.

Question 17

When is histoplasmosis complement fixation serology a good lab to take?

Answer 17

• for acute and chronic and fibrosing mediastinitis (all types except disseminated/diffuse), it is the best test. It is a poor test for disseminated.

However, it has false negatives - not perfect

Question 18

When is treatment indicated in histoplasmosis

Answer 18

• hypoxia
• sx >1month
• disseminated disease

Question 19

How does HIV affect TB?

Answer 19

HIV coinfection rapidly escalates the progression from latent to active TB infection

Question 20

MDR vs XDR TB

Answer 20

-XDR is much worse - resistance to all first line and second line drugs (MDR = just first line)

Question 21

T/F TB is just as contagious as a virus.

Answer 21

False.

it is not as contagious as a virus - requires close contact

Question 22

Infection process of TB.

Answer 22

inhaled–> deposits in the lower airway–> evades the macrophage –> disseminated via blood and lymph–> forms a granuloma

Question 23

Tissue destruction in TB is due to __

Answer 23

host response

Question 24

T/F TB can be exclusively extrapulmonary

Answer 24

true. it is rare but happens

Question 25

T/F Tuberculin skin test can be helpful in active TB

Answer 25

false - it is not recommended - false negatives.