Hypersensitivity Disorders of the Lower Respiratory Tract

Question 1

Generalized lung inflammation of the alveoli and respiratory bronchioles due to organic dusts, molds, foreign proteins, and chemicals. Most commonly seen in 30s to 50s.

Answer 1

Hypersensitivity Pneumonitis

Question 2

Inflammatory reaction to an organic antigen yields sensitization to the antigen. Subsequent, heavy exposure causes neutrophil activaion in small airways and alveoli with mononuclear cell invasion. The release of proteolytic enzymes contributes to the hypersensitivity reaction.

Answer 2

Hypersensitivity pneumonitis

Question 3

Caused by moldy hay

Answer 3

Farmers Lung

Cattle Worker’s Lung

Question 4

Avian proteins

Answer 4

Bird breeder’s lung

Question 5

Caused by water related contamination: humidifiers, air conditioners, heating/cooling systems

Answer 5

Ventilation workers lung

Question 6

Caused by bird feces, feathers, or serum proteins of bird

Answer 6

Bird breeder’s lung

Question 7

Caused by Sawdust from moldy redwood (seen in lumbar mill workers)

Answer 7

Sequoiosis “Saw mill workers” lung

Question 8

Caused by contaminated metalworking fluids

Answer 8

Metal worker’s lung

Question 9

Caused by moldy spores

Answer 9

Mushroom lung

Question 10

Exposure to wheat infested with weevils

Answer 10

Grain Worker’s lung

Question 11

Caused by manufacture of plastics and polyurethane

Answer 11

Chemical workers lungs

Question 12

What are the 3 clinical manifestations of hypersensitivity pneumonitis?

Answer 12

1. Acute hypersensitivity pneumonitis
2. Sub acute (intermittent)
3. Chronic hypersensitivity pneumonitis

Question 13

Rapid onset: Fever, chills, dyspnea, productive cough, chest tightness, malaise occuring 4-8 hours aftere xposure to antigen

Answer 13

Acute hypersensitivity pneumonitis

Question 14

What would you expect to hear when auscultating a patient’s lungs who is in acute hypersensitivity phase of pneumonitis?

Answer 14

Inspiratory crackles

Question 15

What would you expect to see on a biopsy of a patient who is in the acute hypersensitivity phase of pneumonitis?

Answer 15

Micro-nodular interstitial involvement of poorly formed noncaseating granulomas. May be normal.

Question 16

Gradual development of dypnea, producitve cough, anorexia, weight loss, pleuritis. Similar to acute but longer duration and less severe (usually no fever and chills). Associated with more organized granulomas

Answer 16

Sub acute intermittent hypersensitivity pneumonitis

Question 17

What would you expect to see on a CXR in a patient who has sub acute intermittent hypersensitivity pneumonitis?

Answer 17

Micro nodular opacities esp. in lower lung fields

Question 18

What would you expect to see on a biopsy of a patient who has sub acute (intermittent) hypersensitivity pneumonitis.

Answer 18

Noncaseating granulomas (more organized than in sub acute) may be fibrotic

Question 19

Progressive worsening of symptoms. No history of acute epsidoes. Present with slow onset of progressive dyspnea, weight loss, clubbing, tachypnea. Associated with only partial recovery after agent exposure is eliminated.

Answer 19

Chronic hypersensitivity pneumonitis

Question 20

How do you diagnose Hypersensitivity pneumonitis?

Answer 20

CXR

PFTs

Question 21

What would you see on a PFT in a patient who has hypersensitivity pneumonitis

Answer 21

Restrictive componenet, Decrease DLCO, hypoxemia,

Question 22

CBC reveals leukocytosis with a left shit; positive HSN panel

Answer 22

CBC result hypersensitivity pneumonitis

Question 23

How do you manage hypersensitivity pneumonitis?

Answer 23

Avoid allergens

Corticosteroids