Interstitial lung disease is also known as diffuse parenchymal lung disease (DPLD) or diffuse interstitial lung disease.
Interstitial lung disease is a group of lung diseases which affect the interstitium, that is, the tissue and space around the air sacs of the lungs. This large group of disorders cause progressive scarring in the lung tissues and eventually affect the body’s intake capacity of oxygen and breathing capacity. Oxygen transfuse to the other organs are also lowered gradually.
Interstitial lung disease can be caused due to long term or regular exposure to hazardous materials or irritants, such as asbestos, silica dust, coal dust, grains talc etc. Continuous inhalation of these substances build up this group of disorders.
Interstitial lung disease is a group of diseases, and thus can be caused due to inflammation, scarring, or extra fluid (edema). Interstitial pneumonia, idiopathic pulmonary fibrosis, hypersensitivity pneumonitis, acute interstitial pneumonitis, cryptogenic organizing pneumonia (cop), desquamative interstitial pneumonitis, sarcoidosis and asbestosis are some of the types of ILD.
Primary symptoms of interstitial lung disease are short of breath or breathlessness and dry cough. These keep worsening as the condition deteriorates. Other symptoms are weight loss, chest pain, drowsiness etc.
Treatments may help to improve symptoms temporarily or slow the disease's progress but cannot reverse the already scarred tissues of the interstitium. Medications can work widely and are prescribed by the doctors to provide relief. Corticosteroid medicines help to suppress the immune system and thus slow or stabilize the condition. The medications pirfenidone (Esbriet) and nintedanib (Ofev) may slow the rate of disease progression. Oxygen therapy is used for people with excessive breathlessness. It helps to intake greater oxygen, and make breathing easier, reduce blood pressure and other associated complications. Pulmonary rehabilitation helps to improve the daily functioning of the patients. It takes exercises, breathing techniques, emotional support, and nutritional counselling as means to improve the condition. People with severe interstitial lung disease do not respond positively to these treatments. Surgical operations which includes lung transplantation is the only option for them.
Diagnosis of interstitial lung disease involves identifying and determining the causes of the same. As this disease is a combination of many pulmonary disorders, a number of tests are performed to correctly determine the cause of the disease. The lab tests that are necessary are Blood tests which help to determine the condition by the presence of certain substances. Imaging tests like Computerized tomography (CT) scan, Echocardiogram are often prescribed by the doctor for accurate diagnosis. Pulmonary function tests include spirometry and diffusion capacity where patients are required to exhale quickly and forcefully. A tube measures the amount of air the lungs can hold and the ease with which it can be exhaled. Lung tissue (biopsy) in a laboratory include bronchoscopy, bronchoalveolar lavage and surgical biopsy.
Treatment methods for interstitial lung disease vary according to the type of interstitial lung disease and its cause and the patient condition. Antibiotics turn out to be effective in the treatment of ILD. Azithromycin (Zithromax) and levofloxacin (Levaquin) are two drugs that help in the elimination of the bacteria that are responsible for the disease. Continuous inflammation in the lungs causes damage and scarring and to treat this, corticosteroids may be used. Corticosteroids like prednisone and methylprednisolone reduce the activity of the immune system. This also helps to lower the amount of inflammation and also provide relief temporarily to the patient. Oxygen therapy involves artificial inhalation of oxygen to ease breathing and transfer oxygen to the blood and tissues. People with excessive breathlessness are provided with this therapy. Azathioprine (Imuran) and N-acetylcysteine (Mucomyst) are two other drugs used to improve conditions. If the patient fails to response to the above treatment methods, the only option left is surgery or lung transplant. This is done for people with severe or acute lung disease.
People should immediately consult doctors on the slightest occurrence of symptoms. By the time the symptoms are prominent and bothering, the damage might have already been done. Thus, any slightest breathlessness or continuous coughing experiences must be consulted with a doctor. People diagnosed with interstitial lung disease then become eligible for the treatment.
People with no signs and symptoms of ILD or any breathlessness do not need to visit the doctors or undergo any medical treatment and care.
There are some side effects of the treatment methods and medicines used in patients with interstitial lung disease. Oral corticosteroids provided as primary medications have side effects like increased appetite, weight gain, high blood pressure, salt and fluid retention, tendency to bruise easily, depression, psychosis, or hyper excitability, difficulty sleeping, tendency to develop diabetes, peptic ulcer, infections, cataracts and osteoporosis (weakening of the bones). There are other potential risks associated with the treatment. Thus, patients should always consult the doctors.
Post treatment, people should be very careful to avoid anything that could trigger this disease again. Staying away from hazardous substances, taking necessary self care, avoiding smoking and alcohols, breathing in deeply in the open, keeping surroundings clean are a few things they should maintain. In order to improve faster, they should be careful and should take the medicines on time, visit the doctor for monthly check ups, prevent any other associated disease to occur.
Recovery after treatment depends on the condition of the patient, severity and type of disease and the treatment method used. While for some people, with mild disease, recovery is quite fast, for others with excessive lung scarring and other diseases, recovery time is huge. In fact for them, chances of survival is only 5- 10%. Thus, recovery time varies from 3 months to over 3 years or even more.
Medications and drugs which help to treat mild symptoms of breathlessness and dry cough require less expenses. However, for oxygen therapy and lung transplantation, the cost may range between Rs 10,0000- Rs 50,0000/-. If the treatment is a recurrent process, the overall expenditure may rise.
Some forms of interstitial lung disease can be resolved permanently with the help of the treatment. For some others, the condition does not improve even after treatment. A long-term and irreversible scarring takes place and the lungs are gradually damaged with accompanying respiratory failure. Thus, permanence of this condition depends totally on the severity of the disease, its spread and condition and response of the patient to treatment.