Cough may warn of danger for patients with lung-scarring disease

When idiopathic pulmonary fibrosis develops, tissue deep in the lungs becomes thick and scarred, likely due to a response to an unknown substance. The condition affects approximately 100,000 individuals in the United States, and up to half die within three years of being diagnosed.

Almost all patients with idiopathic pulmonary fibrosis experience shortness of breath. The second most common symptom is cough. Shortness of breath is a known warning sign that a patient has a serious form of the disease, but little is known about the importance of cough.To investigate, Christopher Ryerson, MD, of the University of California, San Francisco, and his colleagues studied 242 patients with idiopathic pulmonary fibrosis. They found that cough was present in 84% of patients. It was more common in patients with advanced disease and in those who had never smoked. Also, the presence of cough predicted more rapid disease progression, regardless of the severity of a patient's disease. The study's findings indicate that the presence of cough may predict which patients are likely to die prematurely or need a lung transplant in the near future.

To investigate, Christopher Ryerson, MD, of the University of California, San Francisco, and his colleagues studied 242 patients with idiopathic pulmonary fibrosis. They found that cough was present in 84% of patients. It was more common in patients with advanced disease and in those who had never smoked. Also, the presence of cough predicted more rapid disease progression, regardless of the severity of a patient's disease. The study's findings indicate that the presence of cough may predict which patients are likely to die prematurely or need a lung transplant in the near future.

The authors concluded that patients with idiopathic pulmonary fibrosis who cough may have a worse prognosis compared with patients who do not cough. While additional studies are needed to validate the results, patients who cough may benefit from closer monitoring and more aggressive treatments.

"These findings improve our understanding of cough in idiopathic pulmonary fibrosis," said Dr. Ryerson. "The reason for the association between cough and never having smoked is unknown, but may provide insight into the pathogenesis of cough in idiopathic pulmonary fibrosis and thus prompt future research in this area," he added.