Idiopathic pulmonary fibrosis (IPF) is defined as a specific form of chronic, progressive fibrosing interstitial pneumonia of unknown cause, primarily occurring in older adults, limited to the lungs, and associated with the histopathologic and/or radiologic pattern of usual interstitial pneumonia.
The clinical symptoms of IPF are nonspecific and can be shared with many pulmonary and cardiac diseases. Most patients present with a gradual onset (often > 6 months) of exertional dyspnea and/or a nonproductive cough. Approximately 5% of patients have no presenting symptoms when IPF is diagnosed.
Associated, but uncommon, symptoms include: weight loss, low-grade fevers, fatigue, arthralgias, and myalgias.
The diagnosis of IPF depends upon the clinician integrating and correlating clinical, laboratory, radiologic, and/or pathologic data.
A physical examination may reveal:
- fine bibasilar inspiratory crackles,
- digital clubbing, and
- pulmonary hypertension at rest.
Routine laboratory studies are nonspecific for the diagnosis of IPF; other tests may be needed to exclude other causes of interstitial lung disease.
A 6-minute walk test is often used in the initial and longitudinal clinical assessment of patients with IPF. In patients who desaturate to less than 88% during the test, a progressive decline in the diffusing capacity of the lungs for carbon monoxide (>15% after 6 months) is a strong predictor of increased mortality.
- High-resolution computed tomography (HRCT) scanning is sensitive, specific, and essential for the diagnosis of IPF.
- Chest radiography lacks diagnostic specificity.
- Transthoracic echocardiography detects pulmonary hypertension.
- Bronchoscopy excludes alternative diagnoses.
- Surgical lung biopsy (via open lung biopsy or video-assisted thoracoscopic surgery) provides the best sample for diagnosis.
IPF management strategy should include assessment and treatment of common comorbid medical conditions: chronic obstructive pulmonary disease, obstructive sleep apnea, gastroesophageal reflux disease, and coronary artery disease.
See reference for more information.
Adapted from Medscape Drugs & Diseases. Idiopathic pulmonary fibrosis. Internet. Available at https://emedicine.medscape.com/article/301226-overview. Accessed on April 30, 2018. To view the entire article and all other content on the Medscape Drugs & Diseases site, a free, one-time registration is required.