interstitial lung disease

Question 1

definition?

Answer 1

group of disorders characterized by chronic inflammation and fibrosis of the lungs

Question 2

causes?

Answer 2

1. idiopathic pulmonary fibrosis

EXPOSURE RELATED
2. hypersensitivity pneumonitis (farmer’s lung, pigeon breeder’s lung, chemical worker’s lung)
3.pneumoconioses (coal worker’s lung, asbestosis, silicosis)
4. radiation pneumonitis
5. drug-induced (amiodarone, methotrexate, bleomycin, busulfan)

SECONDARY TO UNDERLYING DISEASE
1. connective tissue (SLE, RA, dermatomyositis)
2. sarcoidosis
3. vasculitis (granulomatosis with polyangiitis)
4. anti-glomerular basement membrane antibody (goodpasture)
5. TB

Question 3

clinical features for all types?

Answer 3

1. progressive dyspnea
2. nonproductive cough
3. digital clubbing in advanced cases
4. bibasilar inspiratory crackles

if reached cor pulmonale: enhanced P2, signs of fluid overload

Question 4

diagnosis?

Answer 4

1. GOLD STANDARD: high resolution CT
   findings:
   -honeycombing (cystic lesions)
   -traction bronchiectasis (dilatation of the bronchi due to fibrosis)
   -pulmonary ossification
   THIS PATTERN is called usual interstitial pneumonia and its CLASSIC AND DIAGNOSTIC FOR idiopathic pulmonary fibrosis without need for histopathology
2. pulmonary function test shows restrictive pattern (low fev1, low fvc, high fev1:fvc) and low total lung capacity and diffusing capacity for CO. this is done to assess severity and tx response
3. invasive testing is done if HRCT is unclear
   -bronchoscopy with bronchoalveolar lavage (cellular analysis can show sarcoidosis)
   -lung biopsy last resort

Question 5

idiopathic pulmonary fibrosis epidemiology? distribution of nodules/fibrosis? prognosis?

Answer 5

-affect males at 60 yrs old
-fibrosis mainly in lower lobes
-respiratory failure occurs within 3-7 years

Question 6

treatment of idiopathic pulmonary fibrosis?

Answer 6

its progressive and non-curable
-counsel on smoking cessation, avoid risk factors, and administer vaccines for covid, influenza, pneumococcal

-offer pulmonary rehab and oxygen therapy
-offer lung transplant
-antifibrotic agents can slow the decline in FVC (pirfenidone, nintedanib)