Overview
Interstitial lung diseases (ILDs), also known as Diffuse Parenchymal Lung Diseases (DPLDs) or Pulmonary Fibrosis, are a diverse group of disorders characterised by inflammation and scarring of the interstitium, which is the tissue surrounding the air sacs (alveoli) in the lungs. This leads to thickening of the interstitium and affects the ability of the lung to transfer oxygen to the bloodstream. ILDs can be acute or chronic and may have various causes and clinical presentations. Most ILDs cause irreversible damage to the lung, and the most serious ILDs are progressive, where the patient’s condition continues to worsen with time.
ILDs can be triggered by a multitude of factors:
- Autoimmune Diseases: Autoimmune diseases, such as rheumatoid arthritis, systemic sclerosis (scleroderma) and systemic lupus erythematosus can cause ILDs.
- Exposure to Environmental Factors: Long-term exposure to factors, such as asbestos fibres, silica dust, environmental toxins, grain dust, bird and animal droppings and indoor hot tubs has been reported to cause ILD.
- Medication: Many drugs, such as chemotherapy drugs (Otrexup, Trexall), some heart medications used to treat irregular heartbeats (Nexterone, Pacerone, Inderal, Innopran), some antibiotics (Macrobid, Macrodantin, Myambutol), and certain anti-inflammatory drugs (Rituxan, Azulfidine), can cause lung damage.
- Infections: Some viral, bacterial, and fungal infections can lead to ILDs.
However, in many cases, the cause remains unknown (idiopathic interstitial pneumonias).
The clinical presentation of ILDs can vary widely depending on the specific type and stage of the disease. Common symptoms include shortness of breath, dry cough, weight loss and fatigue.
Diagnosing ILDs typically involves a combination of:
- Clinical evaluation, including a detailed medical history and physical examination.
- Imaging-based Techniques, such as HRCT Chest, which can reveal characteristic patterns of lung involvement.
- PFTs to assess lung function, including measures of lung volumes and diffusion capacity.
- Biopsy is needed sometimes to confirm the specific type of ILD and guide treatment.
Treatment of ILDs depends on the underlying cause and severity of the disease. It may include:
- Medications: Corticosteroids, immunosuppressants or antifibrotic agents.
- Oxygen Therapy: To improve oxygenation in advanced cases.
- Pulmonary Rehabilitation: Includes exercise programmes and education to manage symptoms.
- Lung Transplant: This is the treatment of choice in severe cases, when other treatments are ineffective.
Overall, ILDs are a complex group of disorders that require careful evaluation and management by pulmonologists and other specialists to optimise outcomes and improve quality of life of the affected individuals.
