Hypersensitivity pneumonitis

Question 1

What is hypersensitivity pneumonitis?

Answer 1

Hypersensitivity reaction following exposure to environmental allergens associated with inflammatory interstitial lung disease

Question 2

What are the clinical features of hypersensitivity pneumonitis?

Answer 2

(Acute) Flu-like symptoms: Fever, chills, malaise, cough, headache
Dyspnea without wheezing
Diffuse fine crackles upon auscultation
(Chronic) Insidious onset of fatigue, productive cough, progressive dyspnea, cyanosis
Bilateral rales
Weight loss

Question 3

What are specific examples of hypersensitivity pneumonitis?

Answer 3

Bird fanciers’ lung avian proteins
Farmers lung spores of Saccharopolyspora rectivirgula
Malt workers’ lung Aspergillus clavatus
Mushroom workers’ lung thermophilic actinomycetes

Question 4

How is hypersensitivity pneumonitis?

Answer 4

(Positive serology) IgG, IgA, or IgM antibodies
(Chest x-ray or CT) Acute -infiltrates may be found in the mid to upper zone
Chronic - ground-glass attenuation with honeycombing
(Pulmonary function test) restrictive pattern
(Pulmonary lavage) Lymphocytic presence

Question 5

What is the treatment for hypersensitivity pneumonitis?

Answer 5

Antigen avoidance

Glucocorticoid therapy