Cryptogenic fibrosing alveolitis (CFA) (or idiopathic pulmonary fibrosis) is a disease of unknown aetiology which is characterised initially by a cellular alveolar infiltrate and later by fibrosis of the alveolar walls.
The mononuclear cell infiltration of the alveoli correlates with acute symptoms whereas the fibrosis correlates with the gradual decline in lung function.
Lung function deteriorates progressively, usually over a period of years; a rapidly progressive form of the disease leads to death within months and is termed the Hamman-Rich syndrome.
It is thought that in CFA there is an abnormal immune response to an unknown stimulus.
Awareness of clinical features of idiopathic pulmonary fibrosis (1)
- be aware of idiopathic pulmonary fibrosis when assessing a patient with
the clinical features listed below and when considering requesting a chest
X-ray or referring to a specialist:
- age over 45 years
- persistent breathlessness on exertion
- persistent cough
- bilateral inspiratory crackles when listening to the chest
- clubbing of the fingers
- normal spirometry or impaired spirometry usually with a restrictive pattern but sometimes with an obstructive pattern
It usually presents with progressive dyspnoea, reduced lung volumes, bilateral lower lobe reticular opacities, and a usual interstial pneumonia pattern on histology. There is no definitive treatment and median survival is approximately 3 years (2)
- however, about 20% of people with the disease survive for more than 5 years. The rate of disease progression can vary greatly. A person's prognosis is difficult to estimate at the time of diagnosis and may only become apparent after a period of careful follow-up (1)