Interstitial Lung Disease is a term used to refer to a particular type of inflammation of the interstitium of the lungs. The interstitium is the tissue that surrounds and separates the tiny air sacs in the lungs. Interstitial lung disease involves an inflammation of this supportive tissue between the air sacs rather than inflammation in the air sacs themselves.

Causes of ILD

Interstitial Lung Disease is felt to be caused by a misdirected immune or healing reaction to a number of factors, like, Infections of the lungs, Toxins in the environment (asbestos, silica dust), Certain medications, Radiation Therapy to the chest, Chronic autoimmune diseases (connective tissue diseases such as lupus, scleroderma and rheumatoid arthritis)

*Sometimes the process of inflammation occurs in the absence of a known cause. When no cause can be identified, this is referred to as idiopathic interstitial lung disease or idiopathic pulmonary fibrosis.

Examples of different types of idiopathic lung diseases include:

1. Usual Interstitial Pneumonitis

2. Bronchitis obliterans with organizing pneumonia

3. Lymphocytic Interstitial Pneumonitis

4. Desquamative Interstitial Pneumonitis

Symptoms of ILD

Decreased lung function is the result of the inflammation present in the supporting interstitial tissues, which leads to scarring and thickening.

Symptoms are related to the reduced efficiency of breathing and corresponding reduced levels of oxygen in the blood. The symptoms depend to a certain extent on the exact cause of the condition, but shortness of breath and a dry cough are the most common symptoms. Signs of chronically reduced oxygen levels in the blood include clubbing (a painless enlargement of the fingertips) and an enlarged heart.

ILD Complications

ILD can lead to serious long term complications. Pulmonary Hypertension, a type of high blood pressure that affects the arteries within the lungs, may develop. Ultimately, right-sided heart failure may result. Respiratory failure is a potentially fatal long term complication of interstitial lung disease.

ILD Diagnosis

Interstitial Lung Disease cannot be simply diagnosed on the basis of a medical history and physical examination. A number of diagnostic tests must be used, because the symptoms of interstitial lung disease overlap with those of many other conditions, including cardiovascular diseases. Blood Tests may help in providing direction in the initial stage and rule out other conditions that may have similar symptoms. Imaging studies, like Chest X-Rays and CT Scans are often the first diagnostic step and may also help rule out other conditions that cause similar symptoms.

Biopsies or washings may be taken of the lungs and airways during bronchoscopy (examination of the airways with a viewing tube).

In some cases, Surgical Biopsies of the lung may be required to obtain an adequate tissue sample for diagnosis.

Treatment for ILD

The choice of treatment depends on a number of factors including the cause of ILD and the overall health status of the patient.

Most commonly, corticosteroid drugs are prescribed to patients. Some patients also benefit from Oxygen Therapy to improve daily functioning.

Oxygen Therapy is required for some patients with interstitial lung disease. Decreased lung function and/or pulmonary hypertension may cause blood oxygen levels to reduce to a very low level. Some may need oxygen all of the time and others only during sleep or exercise. There are various systems that help in delivering oxygen, like oxygen cylinder, concentrators, etc. They allow patients to be active and travel while using oxygen.