“Fleeting pulmonary infiltrates” on sequential chest skiagrams in an individual who suffers from asthma are characteristics of-
**Core Concept**
A fleeting pulmonary infiltrate refers to a transient patch of abnormal lung density visible on a chest radiograph, often associated with an underlying condition such as asthma. These infiltrates can be indicative of bronchiolar obstruction, inflammation, or edema.
**Why the Correct Answer is Right**
Fleeting pulmonary infiltrates in asthma are typically caused by airway obstruction, which leads to atelectasis, air trapping, and subsequent radiographic abnormalities. The airway obstruction can be due to bronchospasm, mucous plugging, or a combination of both. The resulting atelectasis can cause a fleeting pulmonary infiltrate, which may resolve or migrate as the underlying airway obstruction changes.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because fleeting pulmonary infiltrates in asthma are not typically associated with chronic conditions like COPD.
* **Option B:** This option is incorrect because fleeting pulmonary infiltrates in asthma are not usually indicative of a primary lung pathology, such as pneumonia or lung cancer.
* **Option C:** This option is incorrect because fleeting pulmonary infiltrates in asthma are not typically associated with a specific type of lung injury, such as pulmonary embolism.
**Clinical Pearl / High-Yield Fact**
A fleeting pulmonary infiltrate in a patient with asthma can be a sign of worsening airway obstruction, indicating the need for adjustment in treatment, such as increasing bronchodilator therapy or adding corticosteroids.
**Correct Answer: C.**