DPLD can be broken into the following categories (% of all DPLD)
Idiopathic Pulmonary Fibrosis (20%)
Chronic hypersensitivity pneumonitis - mold, bird exposure, mycobacteria, other (20%)
Connective tissue disease related - rheumatoid arthritis, systemic sclerosis (scleroderma), Sjogrens, polymyositis/dermatomyositis (20%)
Sacroidosis (20%)
Pneumoconioses - asbestosis, silicosis, berylliosis (10%)
Other interstitial lung diseases - meds, NSIP, acute or chronic eosinophilic pneumonias (CEP), cryptic organizing pneumonia (COP), acute interstitial pneumonia (AIP), XRT, Vaculitis associated (GPA, EGPA, MPA), other idiopathic (10%)
Exposures (meds, environmental, radiation) or underlying diseases (e.g. sarcoid, CTD, other) as above
For some connective tissue disorders (CTDs), lung findings and symptoms of DPLD will pre-date the diagnosis of CTD
Typically sub-acute, progressive SOB, DOE, chronic cough; can take months (or longer) prior to establishing dx
AIP, COP, AEP tend to present acutely
For some connective tissue disorders (CTDs), lung findings and symptoms will pre-date the diagnosis of CTD
Symptoms suggestive CTD: Reynauds, muscle weakness, joint pain, dry eyes, dry mouth, GERD
Symptoms associated w/vasculitis: nasal congestion/recurrent sinusitis, hemoptysis, joint pain, hematuria
May have hypoxemia
Assess for clubbing, cyanosis
Nasal ulcers, bleeding
Lung exam w/dry sounding crackles
Joint abnormalities or inflammation
Skin findings: e nodosum w/sarcoid, heliotropic rash w/dermatomyositis, scaly papules on knickers (Grotton's papule); sub-cu calcifications (dermatomyositis), thickened skin (sclerodactyly associated w/scleroderma)
Elevated JVP, prominent P2, peripheral edema w/pulmonary hypertension
Lymphadenopathy, hepatomegaly (sarcoid)
Most DPLDs require Video-Assisted Thoracoscopic Surgery (VATS) to make the diagnosis (in addition to history, exam, labs/serologies, PFTs, and imaging to identify as DPLD). Exception is IPF: If typical presentation and imaging, diagnosis can be made without lung biopsy.