Criteria for UIP Pattern

Usual interstitial pneumonia is the most common idiopathic interstitial pneumonia³¹ and carries the worst prognosis.³⁰ UIP is the radiologic and pathologic pattern observed in patients with IPF,⁴⁵ but UIP-like patterns are also caused by secondary conditions such as collagen vascular disease, chronic hypersensitivity pneumonitis, asbestosis, or drug toxicity,³²³³ highlighting the importance of identifying any possible causes of lung disease prior to diagnosing idiopathic UIP.⁴⁵