Fast Five Quiz: Idiopathic Pulmonary Fibrosis Differential Diagnosis

Guy W. Soo Hoo, MD, MPH; Zab Mosenifar, MD


April 04, 2022

Although the presenting signs and symptoms of chronic, severe CHP are like those of IPF, radiographic findings differ. HRCT imaging of patients with CHP typically demonstrate profuse upper lobe fibrotic changes and expiratory air trapping, whereas patients with IPF demonstrate lower lobe fibrotic changes. In addition, emphysema is often revealed on HRCT scans of patients with IPF, but rarely in patients with CHP.

Another important characteristic that distinguishes CHP from IPF is its association with a potential provocative agent. CHP occurs when susceptible individuals develop a delayed fulminant autoimmune response to an inhaled antigen: dust, viruses, bacteria, plants, and fungus. In the acute and subacute stages of CHP, symptom onset is gradual and includes cough, exertional dyspnea, and weight loss. Long-term inflammation leads to fibrosis, mimicking symptoms of IPF.

Saddle PE is not commonly present in patients with CHP.

Learn more about the differential diagnosis of CHP.


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