Pneumonia, Usual Interstitial

Clinical presentation is similar to that of other idiopathic interstitial pneumonias

Median survival is approximately 3 years

Onset at age 55–60 with slight male predominance

Presents as insidious dry cough with months to years of exertional dyspnea

Clubbing is present at diagnosis in 25–50%

Pulmonary function tests: restrictive pattern and decreased diffusion capacity

Antinuclear antibodies (ANA) and rheumatoid factor (RF) are positive in 25% of patients without documented collagen vascular disease

Chest radiographic findings

• Decreased lung volumes with linear or reticular bibasilar or subpleural opacities

• Normal in 2–10% at diagnosis

High-resolution CT scan shows minimal ground-glass and variable honeycombing changes

Biopsy shows nonuniform distribution of fibrosis, with loss of type I pneumocytes and proliferation of alveolar type II cells

Usual interstitial pneumonia can be diagnosed with 90% confidence in patients age > 65 with classic features, avoiding biopsy

Nintedanib and pirfenidone appear to reduce rate of decline in lung function