Overview of Interstitial Lung Disease
(Diffuse Parenchymal Lung Diseases)
Interstitial lung diseases are a heterogeneous group of disorders characterized by alveolar septal thickening, fibroblast proliferation, collagen deposition, and, if the process remains unchecked, pulmonary fibrosis. Interstitial lung diseases can be classified using various criteria (eg, acute vs chronic, granulomatous vs nongranulomatous, known cause vs unknown cause, primary lung disease vs secondary to systemic disease, history of smoking vs no smoking history).
Among the numerous possible causes are most connective tissue disorders and occupational lung exposures and many drugs (see table Causes of Interstitial Lung Disease). A number of interstitial lung diseases of unknown etiology have characteristic histology, clinical features, or presentation and thus are considered unique diseases, including
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Pulmonary Langerhans cell histiocytosis (granulocytosis)
In up to 30% of patients who have interstitial lung diseases with no clear cause, the disorders are distinguished primarily by characteristic histopathologic features; these disorders are termed the idiopathic interstitial pneumonias.
Causes of Interstitial Lung Disease
Category |
Examples |
|
Connective tissue disorders |
Ankylosing spondylitis (rare) Behçet disease (very rare) IgG-4 related disease Undifferentiated connective tissue disease |
|
Drugs |
Selected list: Amphotericin B, bleomycin, busulfan, carbamazepine, chlorambucil, cocaine, cyclophosphamide, diphenylhydantoin, flecainide, heroin, melphalan, methadone, methotrexate, methylphenidate, methysergide, mineral oil (via chronic microaspiration), nitrofurantoin, nitrosoureas, procarbazine, silicone (sc injection), tocainide, vinca alkaloids (with mitomycin) |
|
Genetic disorders |
Fabry disease (rare) Familial pulmonary fibrosis Gaucher disease (rare) Hermansky-Pudlak Syndrome Niemann-Pick disease (rare) Pulmonary alveolar microlithiasis |
|
Idiopathic interstitial pneumonias |
|
|
Infections |
Parasitic infection Mycobacterial infection Viral infection |
|
Occupational and environmental exposure |
Inorganic (selected): Aluminosis (caused by exposure to metallic aluminum powder), asbestosis, baritosis, beryllium disease, coal workers’ pneumoconiosis, exposure to hard metals (eg, cadmium, cobalt, titanium oxide, tungsten, vanadium carbides), radiation fibrosis, siderosis, silicosis, stannosis, talc pneumoconiosis Organic (selected): Bagassosis, bird fancier’s lung, coffee worker’s lung, farmer’s lung, hot tub lung, humidifier lung, malt worker’s lung, maple bark stripper’s lung, mushroom worker’s lung, tea grower’s lung (see Hypersensitivity Pneumonitis) |
|
Vasculitis |
Giant cell arteritis (rare) Polyarteritis nodosa (rare) Takayasu arteritis (rare) |
|
Miscellaneous disorders |
Chronic aspiration Lipoid pneumonia Pulmonary lymphoma |
Drugs Mentioned In This Article
| Drug Name | Select Trade |
|---|---|
cyclophosphamide |
CYTOXAN (LYOPHILIZED) |
methylphenidate |
CONCERTA, RITALIN |
nitrofurantoin |
FURADANTIN, MACROBID, MACRODANTIN |
carbamazepine |
TEGRETOL |
methotrexate |
OTREXUP |
chlorambucil |
LEUKERAN |
procarbazine |
MATULANE |
flecainide |
No US brand name |
mitomycin |
MITOSOL |
methadone |
DOLOPHINE |
melphalan |
ALKERAN |
busulfan |
MYLERAN |
