Conditions

Pneumoconioses is any lung disease, including ILD, caused by exposure to certain inorganic or organic dust particles. These harmful substances can be in places where you spend a lot of time, such as your work, but they can also be environmental.

Pneumoconioses include:

• Asbestosis
• Berylliosis
• Silicosis

Some harmful substances that may cause ILD are:

• Beryllium
• Birds or bird feathers (in down blankets, coats, and pillows)
• Dusts, such as aluminum, antimony, barium, graphite, iron, kaolin, mica, or talc

Granulomas are collections of cells that form in some inflammatory conditions. They can occur all over the body. When granulomas form in the lung tissue, different signs and symptoms of ILD can appear.

Some granulomatous conditions that can lead to ILD are:

• Crohn’s disease
• Hypersensitivity pneumonitis (common causes include dust, mold, and bird feathers)
• Sarcoidosis

Autoimmune disease and connective tissue disease cause the immune system to attack the body. If an autoimmune disease targets the lung, it can cause inflammation and scarring of lung tissue. Sometimes people don’t even know they have an autoimmune disorder until after they develop ILD.

Autoimmune diseases that can cause ILD include:

• Polymyositis dermatomyositis (see The Myositis Foundation)
• Rheumatoid arthritis (see Arthritis Foundation)
• Scleroderma (see Scleroderma Foundation)
• Sjögren’s syndrome (see Sjögren’s Foundation)

Some medications play a role in the development of ILD. Factors include the:

• Type of medicine
• Amount of time you take it
• Dosage 

Drugs that can lead to ILD include:

• Antibiotics (nitrofurantoin)
• Cancer treatments (bleomycin) and chemotherapy
• Heart medications (amiodarone)
• Immunotherapy drugs (nivolumab, pembrolizumab)
• Medications for rheumatoid arthritis
• Methotrexate
• Nitrofurantoin

Some types of ILD are extremely rare but have specific features that distinguish them from other ILDs. These features can be noticed in a computed tomography (CT) scan or in lab tests.

Some rare types of ILDs include:

• Amyloidosis
• Eosinophilic pneumonia
• Familial ILD
• Lymphangioleiomyomatosis (LAM)
• Radiation pneumonitis
• Vasculitis (see Vasculitis Foundation)
• Those related to vaping or inhaling marijuana-like substances

Radiation helps treat many cancers. But it sometimes causes ILD. People can develop ILD weeks or years after having radiation treatments.

More than half of ILD cases are idiopathic. This means they have no known cause. IPF is the best example of an idiopathic ILD. Idiopathic ILDs can be associated with smoking or other rare causes. Sometimes they are unclassifiable.

The types of idiopathic ILD are:

• Acute/Subacute: Severe and sudden over days to weeks or months
  • Acute interstitial pneumonia (AIP)
  • Cryptogenic organizing pneumonia (COP)
• Chronic: Discomfort that is ongoing or recurring

Acute idiopathic ILDs usually have symptoms like pneumonia, but they are not infections. Doctors do not treat acute ILDs with antibiotics.

Chronic fibrosing ILDs may take time to cause symptoms. By the time someone has symptoms, the lung already has scarring that is not reversible. Idiopathic pulmonary fibrosis (IPF) is one type of a chronic fibrosing ILD with no identifiable cause (some known causes can also trigger fibrosis). Another type is chronic nonspecific interstitial pneumonia (NSIP).

Some ILDs are extremely rare, but they have specific features that distinguish them from other ILDs. Rare idiopathic ILDs include:

• Lymphoid interstitial pneumonia (LIP)
• Pleuroparenchymal fibroelastosis (PPFE)

Some ILDs do not fall into any particular group. They can still be treated. Your doctor may recommend a lung biopsy to help determine your treatment options.

Smoking rarely causes ILD. If a smoker develops ILD, the first treatment step is to stop smoking. ILDs caused by smoking are:

• Desquamative interstitial pneumonia (DIP)
• Pulmonary langerhans cell histiocytosis (PLCH)
• Respiratory bronchiolitis-ILD (RBILD)

Some forms of ILD tend to run in families. For example, idiopathic pulmonary fibrosis (IPF) runs in families 10% to 15% of the time.

Genetic changes that cause IPF are passed down from a parent to a child. Genetic tests for IPF are not a part of a routine workup. Ask your lung doctor about testing if more than one person in your family has pulmonary fibrosis.