# Secondary Spontaneous Pneumothorax in a Patient With Interstitial Lung Disease Undergoing Routine Outpatient Pulmonary Function Tests

## TL;DR

A patient with interstitial lung disease experienced a pneumothorax after pulmonary function tests, highlighting a rare but serious risk.

## Contribution

This case report highlights a rare complication of pneumothorax in interstitial lung disease patients undergoing pulmonary function tests.

## Key findings

- A 64-year-old female with interstitial lung disease developed a pneumothorax after pulmonary function tests.
- The patient required emergency chest tube placement and doxycycline pleurodesis for treatment.
- Subcutaneous emphysema occurred, requiring replacement of the chest tube with a pigtail catheter.

## Abstract

We present the case of a 64-year-old female with a past medical history significant for unclassified interstitial lung disease (ILD) from suspected hypersensitivity pneumonitis secondary to chronic mold exposure with steroid responsiveness and prior pneumothorax. The patient developed shortness of breath and pleuritic chest pain after undergoing routine outpatient pulmonary function tests (PFTs). She was immediately transferred to the emergency department and found to have a moderate left basilar pneumothorax. She underwent emergent surgical chest tube placement followed by doxycycline pleurodesis. Repeat chest imaging showed inadvertent retraction of the chest tube and extensive subcutaneous emphysema. The surgical chest tube was replaced by a pigtail catheter with an improvement of subcutaneous emphysema. This case demonstrates the development of a rare but serious complication of pneumothorax that could occur in patients who have ILD undergoing routine PFTs. Clinicians should be aware of this risk when patients who have ILD present for PFTs and counsel them to seek immediate medical attention if they develop signs of acute onset dyspnea after performing PFTs.