Interstitial lung disease

Background

• General group of diseases that involve the lung parenchyma
• Grouped together because of similar clinical, physiologic, radiographic, or pathologic findings
• Specific diseases separated into ones with known causes and idiopathic
• Treatment and prognosis differs between specific diseases
• Examples of specific diseases: interstitial pneumonia, hypersensitivity pneumonitis, cryptogenic organizing pneumonia, acute interstitial pneumonitis, sarcoidosis, idiopathic pulmonary fibrosis

Clinical Features

• Symptoms: progressive exertional dyspnea, persistent nonproductive cough, hemoptysis, pleuritic chest pain
• History of occupational exposure: asbestosis, silicosis
• Abnormal chest imaging or pulmonary function tests
• Take detailed history making sure to focus on past medical history (connective tissue disease, inflammatory bowel disease, malignancy), smoking history, family history, medications, occupational and environmental exposures
• Physical exam is generally nonspecific

Differential Diagnosis

• Pneumonia
• Asbestosis
• Berylliosis
• Pulmonary edema
• Coal worker's pneumoconiosis
• Cryptogenic organizing pneumonia
• Drug induced pulmonary toxicity
• Farmer's lung
• Hypersensitivity pneumonitis
• Interstitial pulmonary fibrosis
• Collagen-vascular disease
• Lung malignancy
• Restrictive lung disease
• Sarcoidosis
• Silicosis

Evaluation

Work up and test results differ between types of interstitial lung diseases. Below are common studies obtained to determine disease. See page for specific disease for specific labs/imaging and findings.

• CBC/CMP
• Serologic studies: ANA, Rheumatoid factor
• Imaging: Chest x-ray, chest CT
• Pulmonary function tests
• Cardiac ECHO
• Bronchoalveolar lavage
• Lung biopsy

Management

• Management differs between specific types of interstitial lung diseases. This is why it is important to determine specific cause of disease. See specific disease page for management.

Disposition

• Depending on how stable the patient is, patient can be admitted for work up or discharged for outpatient work up.
• Important to determine acute vs chronic symptoms.

See Also

• Sarcoidosis
• Idiopathic pulmonary fibrosis

References

• <Bradley B, et al. Interstitial lung disease guideline: the British Thoracic Society in collaboration with the Thoracic Society of Australia and New Zealand and the Irish Thoracic Society. Thorax 2008; 63 Suppl 5:v1./>
• <Pipavath S, Godwin JD. Imaging of interstitial lung disease. Clin Chest Med 2004; 25:455./>
• <Martinez FJ, Flaherty K. Pulmonary function testing in idiopathic interstitial pneumonias. Proc Am Thorac Soc 2006; 3:315./>
• <Schwartz M, King Jr TE. Interstitial Lung disease, 5th ed, People's Medical Clearing House, Shelton, CT 2011./>
• <Raghu G, et al. An official ATS/ERS/JRS/ALAT statement: idiopathic pulmonary fibrosis: evidence-based guidelines for diagnosis and management. Am J Respir Crit Care Med 2011; 183:788./>
• <Garcia CK, Raghu G. Inherited interstitial lung disease. Clin Chest Med 2004; 25:421./>