On examination, there is gross clubbing of the fingernails and toenails. The movements of chest on the affected side are reduced. The trachea is shifted if there is fibrosis of the upper lobe. In fibrosis o the lower lobe, there is shifting of the heart and hence the apex beat. Percussion not is also dull over the affected area. Numerous end-inspiratory crepitations are also audible on auscultation.
The diagnosis of pulmonary fibrosis is assisted by the use of the following investigations.
Treatment with corticosteroids is beneficial in around 30% of the patients. A trial of prednisolone with 40 to 60 mg per day is started in the patients in the patients with progressive disease. The response to treatment is evaluated over a period of 6 to 8 weeks. If the response is good, the dose is reduced to 5 or 10 mg per day. If there is no response, the dosage is tapered and stopped.
Azathioprine or cyclophosphamide may be added if there is no response to prednisolone therapy. They are also used if there is a relapse on reducing the dose of prednisolone .
In severe disease, lung transplantation should be considered as the definitive cure.
Once fibrosis has developed, it is not reversible. The prognosis is good if the disease is detected early and its progression stopped through adequate treatment. If fibrosis is extensive, lung transplantation may be the only option.
Pulmonary fibrosis can occur due to a number of well-established causes that are listed below .
Other less important causes of pulmonary fibrosis include the following.
The epidemiology of pulmonary fibrosis is not very well documented. It is estimated that up to 5 million people are affected worldwide. The incidence of idiopathic pulmonary fibrosis is higher in people over the age of 50 years.
The initial insult in the development of pulmonary fibrosis is injury to the epithelial surface. This leads to the development of inflammation in the air spaces and the walls of the alveoli, leading to an acute phase of alveolitis. The disease then spreads to the adjacent portions of the interstitium and vasculature, ultimately leading to fibrosis.
It has been suggested that fibrosis is caused by the release of fibronectin and growth factors from alveolar macrophages following tissue injury caused by the release of oxidants from neutrophils, eosinophils and macrophages .
Histologically, pulmonary fibrosis is characterized by cellular infiltration along with thickening and fibrosis of the walls of the alveoli. The degree of fibrosis is variable and is often progressive.
Idiopathic pulmonary fibrosis can not be prevented. However, pulmonary fibrosis of known etiology can be prevented by avoiding exposure to silica dust, asbestos, coal dust and beryllium. The people who come in contact with these dusts in their occupation should use proper masks.
The overuse of methotrexate, amiodarone, hydralazine, bleomycin and busuphan should be avoided.
Pulmonary fibrosis is not a single disease entity. It is a part of a group of disorders that are known as interstitial lung diseases. The common features in these disease include:
Pulmonary fibrosis refers to the thickening and hardening of the walls of the alveoli of the lungs. This condition causes a reduction in the amount of expansion and capacity of the lungs. As a result, the function of the lungs is rendered short and the patient becomes breathless upon any kind of exertion. The disease is progressive if not treated properly. Lung transplantation may be the only treatment option in advanced cases.