Thank you to James for presenting a fascinating case of middle aged woman with a questionable history of ILD presenting with acute worsening of a chronic cough concerning for an ILD flare vs. undiagnosed infection.
- In a patient presenting with an ILD ALWAYs rule out infection & look for an underlying cause.
- When BAL is negative x48h, then you can consider empiric steroids. Steroids are really only useful for acute idiopathic ILD (COP and AEP) and for some ILDs from known causes (see “approach to ILD” below)!
- Idiopathic pulmonary fibrosis (IPF) & nonspecific interstitial pneumonia (NSIP) p/w a restrictive PFT pattern, however hypersensitivity pneumonitis (HS) can present with air trapping and obstructive +/-restrictive PFTs
- Back to the Jen B rule – A patient is considered immunosuppressed if they take ~20 mg of Prednisone for 2-3 (remember PCP prophylaxis)
An Approach to ILD
Broken down into 4 categories
- Known Causes – drugs, RA or CTD,
- Idiopathic interstitial pneumonia
- Granulomatous disease (eg, Sarcoid)
- Other causes
And a few more pearls on ILD
- Try to find any underlying cause!
- Bronchial biopsy can be very useful if it can be obtained!
- Alphabet soup: What about UIP (usual interstitial pneumonia) This is pattern – that is characteristic of end-stage IPF (see chart below).
- Steroids are useful in acute idiopathic ILD and some forms of ILDs from known causes (eg connective tissue diseases). NOT useful in other forms. However, for critically ill patients in the ICU with respiratory failure from ILD flare, oftentimes our pulmonary experts will still recommend it
Table to better understand the alphabet soup!
|Histological Pattern||Clinical Syndrome||Associated Diseases|
|Usual interstitial pneumonia||Idiopathic pulmonary fibrosis (IPF)||Connective tissue disease (CTD), drugs, asbestosis|
|Nonspecific interstitial pneumonia (NSIP)||Idiopathic NSIP||CTD, drugs, HP|
|Desquamative intestinal pneumonia (DIP)||Idiopathic DIP||Smoking, CTD, drugs, toxic inhalation|
|Organizing Pneumonia||Cryptogenic OP|
|Diffuse Alveolar Damage (DAD)||Aute interstitial pneumonia||Infection, aspiration, trauma, sepsis, pancreatitis|