Interstitial Lung Disease
- Boot Camp
- Aug 16, 2023
- 2 min read
Updated: Sep 14, 2024
Physical Examination
General examination:
Tachypnoea (advanced disease)
Central cyanosis
Chest inspection:
Flattened chest (affected side)
Palpation:
Reduced chest expansion
Increased tactile vocal fremitus and resonance (difficult to appreciate)
Percussion:
Dullness to percussion (affected zones)
Auscultation:
Fine end-inspiratory crepitations (affected zones)
Unaffected by coughing
Other signs:
Evidence of pulmonary hypertension
Signs of treatment, such as steroid purpura and oxygen supplementation
If associated with underlying causes:
Slate grey appearance from amiodarone
Peripheral symmetrical deforming polyarthropathy (swan neck deformity, Z thumb, ulnar deviation at wrist, may have nodules) from rheumatoid arthritis
Cutaneous signs of systemic sclerosis, lupus, etc. from connective tissue disease
Question mark posture, protuberant abdomen from ankylosing spondylitis
May have radiation tattoo on chest wall, lymphadenopathy from radiation
Cutaneous signs of sarcoidosis
Investigations
Laboratory investigations:
Full blood count, erythrocyte sedimentation rate (ESR) or C-reactive protein (CRP): to assess for evidence of inflammation or infection
Renal and liver function tests: to assess for organ dysfunction which may impact treatment options or require dose adjustments
Serum autoantibodies: to screen for autoimmune diseases that can be associated with interstitial lung disease (e.g. anti-nuclear antibody, anti-SSA/SSB, anti-Jo-1, anti-Scl-70)
Serum immunoglobulins: to assess for hypergammaglobulinemia which may suggest sarcoidosis or connective tissue disease
Imaging investigations:
Chest X-ray: to evaluate for evidence of interstitial lung disease, assess the extent and distribution of disease, and exclude other lung pathologies
High-resolution computed tomography (HRCT) of the chest: to confirm the presence of interstitial lung disease, assess the pattern and extent of disease, and guide further management
Invasive investigations:
Bronchoalveolar lavage (BAL): to obtain fluid and cells from the lungs for microbiological and cytological analysis, and exclude infection
Transbronchial lung biopsy (TBLB): to obtain tissue samples for histological analysis and confirm the diagnosis of interstitial lung disease
Video-assisted thoracoscopic surgery (VATS) lung biopsy: for cases where TBLB is inconclusive or not possible, to obtain larger tissue samples for diagnosis
Other investigations:
Pulmonary function tests (PFTs): Restrictive pattern
Exercise testing: to assess exercise tolerance and determine the need for oxygen therapy
Cardiac evaluation: to assess for evidence of pulmonary hypertension or cor pulmonale which may require specific treatment
Management
General management:
Education and advice on smoking cessation
Pulmonary rehabilitation
Annual influenza and pneumococcal vaccination
Airway clearance techniques (e.g., chest physiotherapy, positive expiratory pressure devices)
Regular follow-up with a respiratory specialist or multidisciplinary team
Psychological support for patients with significant symptoms or impact on quality of life
Medical management:
Antibiotics for exacerbations
Mucolytic agents (e.g., carbocisteine, dornase alfa) to help clear mucus
Bronchodilators (e.g., salbutamol) to help with airflow obstruction
Inhaled corticosteroids to reduce inflammation
Oxygen therapy for hypoxemia
Surgical management:
Surgery may be considered for localized disease, particularly if the bronchiectasis is causing significant symptoms or hemoptysis
Lobectomy, segmentectomy, or pneumonectomy may be performed depending on the extent of the disease
Causes of Interstitial Lung Disease
Idiopathic Interstitial Pneumonias (IIPs)
Connective Tissue Disease-associated ILD (CTD-ILD): Rheumatoid arthritis (RA), Systemic sclerosis (SSc), Systemic lupus erythematosus (SLE)
Hypersensitivity Pneumonitis (HP): Extrinsic allergic alveolitis
Occupational and Environmental ILD: Asbestosis, Silicosis
Drug-induced ILD: Amiodarone, Bleomycin, Methotrexate, Nitrofurantoin, Sulfasalazine
Sarcoidosis
Vasculitis : Granulomatosis with polyangiitis)
Miscellaneous causes: Radiation pneumonitis