Interstitial lung disease
Updates to Article Attributes
Interstitial lung disease (ILD) is an umbrella term that encompasses a large number of disorders that are characterised by diffuse cellular infiltrates in a periacinar location. The spectrum of conditions included is broad, ranging from occasional self-limited inflammatory processes to severe debilitating fibrosis of the lungs.
Terminology
Interstitial lung disease is considered a misnomer by some, as many of the diseases also involve the alveolar spaces.
Clinical presentation
Interstitial lung diseases classically produce the "3Cs": cough, clubbing of the nails, and coarse crackles on auscultation 6.
Functional respiratory tests commonly show an abnormal restrictive pattern and reduced diffusing capacity.
Pathology
Aetiology
The radiological appearances are not specific for the underlying cause of diffuse lung disease in many cases. It is therefore key to determine whether there is an underlying cause for the changes. A number of precipitants can cause diffuse interstitial disease such as:
smoking 1
organic dusts (causing hypersensitivity pneumonitis)
inorganic dusts (causing pneumoconioses)
gases or fumes
drugs
radiation
infection
Eliciting a history of underlying systemic disease is also helpful since they may involve the lungs in a diffuse and infiltrative manner. Examples include:
granulomatous diseases, e.g. sarcoidosis, Langerhans cell histiocytosis
-
neoplasia
primary, e.g. lymphoma, other lymphoproliferative diseases
secondary, e.g. pulmonary metastases, lymphangitis carcinomatosis
vasculitis
inherited diseases, e.g. neurofibromatosis
-
autoimmune and collagen vascular diseases (collagen vascular disease related interstitial pneumonitis) 3
-
immune dysregulation
miscellaneous, e.g. amyloidosis, alveolar proteinosis
Where a cause is not determined, the idiopathic interstitial pneumonia (IIP) should be considered:
usual interstitial pneumonia (UIP): idiopathic pulmonary fibrosis
-
non-UIP IIP
non-specific interstitial pneumonia (NSIP): non-smokers
cryptogenic organising pneumonia (COP): previously termed BOOP
respiratory bronchiolitis-interstitial lung disease (RB-ILD): smokers
desquamative interstitial pneumonia (DIP): end-state of RB-ILD
-
other entities
Mnemonic: All Idiopathic Chronic Lung Diseases aRe Nonspecific
Radiographic features
The diffuse lung diseases tend to cause infiltrative opacification in the periphery of the lung, but patterns vary among the different aetiologies. Please refer to the articles in each specific aetiology listed above for specific details on their imaging pattern.
Follow up
Follow and monitoring will depend on a multitude of factors such as symptoms and other co-morbidities etc. While no strict consensus recommendation are available in relation to imaging follow-up for patients with progressive fibrosing forms,. Many consider an HRCT at the patient’s initial presentation and then every 12–18 months to assess for progression dependent on symptoms etc 11.
See also
interstitial lung pattern - radiograph
-<li>smoking <sup>1</sup>-</li>-<li>organic dusts (causing <a href="/articles/hypersensitivity-pneumonitis">hypersensitivity pneumonitis</a>)</li>-<li>inorganic dusts (causing <a href="/articles/pneumoconiosis">pneumoconioses</a>)</li>-<li>gases or fumes</li>-<li>drugs</li>-<li>radiation</li>-<li>infection</li>- +<li><p>smoking <sup>1</sup></p></li>
- +<li><p>organic dusts (causing <a href="/articles/hypersensitivity-pneumonitis">hypersensitivity pneumonitis</a>)</p></li>
- +<li><p>inorganic dusts (causing <a href="/articles/pneumoconiosis">pneumoconioses</a>)</p></li>
- +<li><p>gases or fumes</p></li>
- +<li><p>drugs</p></li>
- +<li><p>radiation</p></li>
- +<li><p>infection</p></li>
-<li>granulomatous diseases, e.g. <a href="/articles/sarcoidosis-1">sarcoidosis</a>, <a href="/articles/pulmonary-langerhans-cell-histiocytosis">Langerhans cell histiocytosis</a>-</li>-<li>neoplasia<ul>-<li>primary, e.g. <a href="/articles/pulmonary-lymphoma">lymphoma</a>, other lymphoproliferative diseases</li>-<li>secondary, e.g. <a href="/articles/pulmonary-metastases">pulmonary metastases</a>, <a href="/articles/lymphangitic-carcinomatosis">lymphangitis carcinomatosis</a>-</li>-</ul>-</li>-<li>vasculitis</li>-<li>inherited diseases, e.g. <a href="/articles/neurofibromatosis">neurofibromatosis</a>-</li>-<li>autoimmune and collagen vascular diseases (<a href="/articles/collagen-vascular-disease-related-interstitial-pneumonitis">collagen vascular disease related interstitial pneumonitis</a>) <sup>3</sup><ul>-<li><a href="/articles/systemic-lupus-erythematosus">systemic lupus erythematosus</a></li>-<li><a href="/articles/rheumatoid-arthritis">rheumatoid arthritis</a></li>-<li><a href="/articles/scleroderma">progressive systemic sclerosis</a></li>-<li>-<a href="/articles/anti-jo-1-antibody-positive-interstitial-lung-disease-1">anti-Jo-1 antibody positive interstitial lung disease </a><ul>- +<li><p>granulomatous diseases, e.g. <a href="/articles/sarcoidosis-1">sarcoidosis</a>, <a href="/articles/pulmonary-langerhans-cell-histiocytosis">Langerhans cell histiocytosis</a></p></li>
-<a href="/articles/dermatomyositis">dermatomyositis</a> and <a href="/articles/polymyositis">polymyositis</a>-</li>-<li><a href="/articles/anti-synthetase-syndrome-1">antisynthetase syndrome </a></li>- +<p>neoplasia</p>
- +<ul>
- +<li><p>primary, e.g. <a href="/articles/pulmonary-lymphoma">lymphoma</a>, other lymphoproliferative diseases</p></li>
- +<li><p>secondary, e.g. <a href="/articles/pulmonary-metastases">pulmonary metastases</a>, <a href="/articles/lymphangitic-carcinomatosis">lymphangitis carcinomatosis</a></p></li>
-<li><a href="/articles/anti-srp-autoantibody-associated-interstitial-lung-disease">anti-SRP autoantibody associated interstitial lung disease</a></li>-<li><a href="/articles/ankylosing-spondylitis-1">ankylosing spondylitis</a></li>-<li><a href="/articles/sjogren-syndrome-1">Sjögren syndrome</a></li>-<li><a href="/articles/mixed-connective-tissue-disease">mixed connective tissue disease</a></li>- +<li><p>vasculitis</p></li>
- +<li><p>inherited diseases, e.g. <a href="/articles/neurofibromatosis">neurofibromatosis</a></p></li>
-<a href="/articles/psoriasis">psoriasis</a> - <a href="/articles/pulmonary-manifestations-of-psoriasis">pulmonary manifestations of psoriasis</a> </li>-<li><a href="/articles/interstitial-pneumonia-with-autoimmune-features">interstitial pneumonia with autoimmune features</a></li>-<li>-<a href="/articles/primary-biliary-cholangitis">primary biliary cholangitis</a> / <a href="/articles/primary-biliary-cholangitis">primary biliary cirrhosis</a> <sup>7</sup>-</li>- +<p>autoimmune and collagen vascular diseases (<a href="/articles/collagen-vascular-disease-related-interstitial-pneumonitis">collagen vascular disease related interstitial pneumonitis</a>) <sup>3</sup></p>
- +<ul>
- +<li><p><a href="/articles/systemic-lupus-erythematosus">systemic lupus erythematosus</a></p></li>
- +<li><p><a href="/articles/rheumatoid-arthritis">rheumatoid arthritis</a></p></li>
- +<li><p><a href="/articles/scleroderma">progressive systemic sclerosis</a></p></li>
- +<li>
- +<p><a href="/articles/anti-jo-1-antibody-positive-interstitial-lung-disease-1">anti-Jo-1 antibody positive interstitial lung disease</a></p>
- +<ul>
- +<li><p><a href="/articles/dermatomyositis">dermatomyositis</a> and <a href="/articles/polymyositis">polymyositis</a></p></li>
- +<li><p><a href="/articles/anti-synthetase-syndrome-1">antisynthetase syndrome</a></p></li>
-<li>immune dysregulation <ul><li>e.g. <a href="/articles/hiv">HIV</a> - <a href="/articles/hiv-associated-interstitial-lung-diseases">HIV associated interstitial lung diseases</a> <sup>8</sup>-</li></ul>-</li>-<li>miscellaneous, e.g. <a href="/articles/amyloidosis">amyloidosis</a>, <a href="/articles/pulmonary-alveolar-proteinosis">alveolar proteinosis</a>- +<li><p><a href="/articles/anti-srp-autoantibody-associated-interstitial-lung-disease">anti-SRP autoantibody associated interstitial lung disease</a></p></li>
- +<li><p><a href="/articles/ankylosing-spondylitis-1">ankylosing spondylitis</a></p></li>
- +<li><p><a href="/articles/sjogren-syndrome-1">Sjögren syndrome</a></p></li>
- +<li><p><a href="/articles/mixed-connective-tissue-disease">mixed connective tissue disease</a></p></li>
- +<li><p><a href="/articles/psoriasis">psoriasis</a> - <a href="/articles/pulmonary-manifestations-of-psoriasis">pulmonary manifestations of psoriasis</a> </p></li>
- +<li><p><a href="/articles/interstitial-pneumonia-with-autoimmune-features">interstitial pneumonia with autoimmune features</a></p></li>
- +<li><p><a href="/articles/primary-biliary-cholangitis">primary biliary cholangitis</a> / <a href="/articles/primary-biliary-cholangitis">primary biliary cirrhosis</a> <sup>7</sup></p></li>
- +</ul>
-</ul><p>Where a cause is not determined, the <a href="/articles/idiopathic-interstitial-pneumonias">idiopathic interstitial pneumonia (IIP)</a> should be considered:</p><ul>-<a href="/articles/usual-interstitial-pneumonia-uip">usual interstitial pneumonia (UIP)</a>: <a href="/articles/idiopathic-pulmonary-fibrosis">idiopathic pulmonary fibrosis</a>- +<p>immune dysregulation </p>
- +<ul><li><p>e.g. <a href="/articles/hiv">HIV</a> - <a href="/articles/hiv-associated-interstitial-lung-diseases">HIV associated interstitial lung diseases</a> <sup>8</sup></p></li></ul>
-<li>non-UIP IIP<ul>-<li>-<a href="/articles/non-specific-interstitial-pneumonia-nsip">non-specific interstitial pneumonia (NSIP)</a>: non-smokers</li>-<li>-<a href="/articles/cryptogenic-organising-pneumonia-cop">cryptogenic organising pneumonia (COP)</a>: previously termed BOOP</li>-<li>-<a href="/articles/respiratory-bronchiolitis-interstitial-lung-disease-rb-ild">respiratory bronchiolitis-interstitial lung disease (RB-ILD)</a>: smokers</li>-<li>-<a href="/articles/desquamative-interstitial-pneumonia">desquamative interstitial pneumonia (DIP)</a>: end-state of RB-ILD</li>- +<li><p>miscellaneous, e.g. <a href="/articles/amyloidosis">amyloidosis</a>, <a href="/articles/pulmonary-alveolar-proteinosis">alveolar proteinosis</a></p></li>
- +</ul><p>Where a cause is not determined, the <a href="/articles/idiopathic-interstitial-pneumonias">idiopathic interstitial pneumonia (IIP)</a> should be considered:</p><ul>
- +<li><p><a href="/articles/usual-interstitial-pneumonia-uip">usual interstitial pneumonia (UIP)</a>: <a href="/articles/idiopathic-pulmonary-fibrosis">idiopathic pulmonary fibrosis</a></p></li>
-<a href="/articles/lymphocytic-interstitial-pneumonitis-1">lymphoid interstitial pneumonia (LIP)</a>: women</li>-<li><a href="/articles/acute-interstitial-pneumonitis">acute interstitial pneumonitis (AIP)</a></li>- +<p>non-UIP IIP</p>
- +<ul>
- +<li><p><a href="/articles/non-specific-interstitial-pneumonia-nsip">non-specific interstitial pneumonia (NSIP)</a>: non-smokers</p></li>
- +<li><p><a href="/articles/cryptogenic-organising-pneumonia-cop">cryptogenic organising pneumonia (COP)</a>: previously termed BOOP</p></li>
- +<li><p><a href="/articles/respiratory-bronchiolitis-interstitial-lung-disease-rb-ild">respiratory bronchiolitis-interstitial lung disease (RB-ILD)</a>: smokers</p></li>
- +<li><p><a href="/articles/desquamative-interstitial-pneumonia">desquamative interstitial pneumonia (DIP)</a>: end-state of RB-ILD</p></li>
- +<li><p><a href="/articles/lymphoid-interstitial-pneumonia">lymphoid interstitial pneumonia (LIP)</a>: women</p></li>
- +<li><p><a href="/articles/acute-interstitial-pneumonitis">acute interstitial pneumonitis (AIP)</a></p></li>
-<li>other entities<ul>-<li><a href="/articles/combined-pulmonary-fibrosis-and-emphysema">combined pulmonary fibrosis and emphysema (CPFE)</a></li>-<li><a href="/articles/pleuroparenchymal-fibroelastosis">idiopathic pleuroparenchymal fibroelastosis</a></li>- +<li>
- +<p>other entities</p>
- +<ul>
- +<li><p><a href="/articles/combined-pulmonary-fibrosis-and-emphysema">combined pulmonary fibrosis and emphysema (CPFE)</a></p></li>
- +<li><p><a href="/articles/pleuroparenchymal-fibroelastosis">idiopathic pleuroparenchymal fibroelastosis</a></p></li>
-</ul><p><strong>Mnemonic:</strong> <a href="/articles/idiopathic-interstitial-pneumonia-mnemonic-2">All Idiopathic Chronic Lung Diseases aRe Nonspecific</a></p><h4>Radiographic features</h4><p>The diffuse lung diseases tend to cause infiltrative opacification in the periphery of the lung, but patterns vary among the different aetiologies. Please refer to the articles in each specific aetiology listed above for specific details on their imaging pattern. </p><h4>See also</h4><ul>-<li><a href="/articles/interstitial-lung-abnormality">interstitial lung abnormality</a></li>-<li>-<a href="/articles/interstitial-lung-pattern-radiograph">interstitial lung pattern</a> - radiograph</li>- +</ul><p><strong>Mnemonic:</strong> <a href="/articles/idiopathic-interstitial-pneumonia-mnemonic-2">All Idiopathic Chronic Lung Diseases aRe Nonspecific</a></p><h4>Radiographic features</h4><p>The diffuse lung diseases tend to cause infiltrative opacification in the periphery of the lung, but patterns vary among the different aetiologies. Please refer to the articles in each specific aetiology listed above for specific details on their imaging pattern. </p><h4>Follow up </h4><p>Follow and monitoring will depend on a multitude of factors such as symptoms and other co-morbidities etc. While no strict consensus recommendation are available in relation to imaging follow-up for patients with progressive fibrosing forms,. Many consider an HRCT at the patient’s initial presentation and then every 12–18 months to assess for progression dependent on symptoms etc <sup>11</sup>.</p><h4>See also</h4><ul>
- +<li><p><a href="/articles/interstitial-lung-abnormality">interstitial lung abnormality</a></p></li>
- +<li><p><a href="/articles/interstitial-lung-pattern-radiograph">interstitial lung pattern</a> - radiograph</p></li>
References changed:
- 11. Nambiar A, Walker C, Sparks J. Monitoring and Management of Fibrosing Interstitial Lung Diseases: A Narrative Review for Practicing Clinicians. Ther Adv Respir Dis. 2021;15:17534666211039771. <a href="https://doi.org/10.1177/17534666211039771">doi:10.1177/17534666211039771</a> - <a href="https://www.ncbi.nlm.nih.gov/pubmed/34477452">Pubmed</a>