Background: COVID-19 reportedly causes various complications during its clinical course. Pneumothorax is one such complication, and has recently gained attention; however, the clinical features of pneumothorax associated with COVID-19 have not been fully elucidated.

Aims: This study aimed to collect cases of pneumothorax associated with COVID-19 to clarify their clinical features.

Methods: We retrospectively analysed patients who developed pneumothorax within 6 months after COVID-19 diagnosis. We investigated background factors, COVID-19 severity and treatment, timing of pneumothorax onset, treatment modalities, treatment duration, and prognosis of these patients.

Results: In total 16 patients were diagnosed with pneumothorax within 6 months of COVID-19 diagnosis. Their mean age at incidence was 72.9 (range 50.0?96.0) years. More than 80% were male (87.5%) and had a history of smoking (81.3%). The most frequent comorbidity was hypertension, followed by type 2 diabetes mellitus and COPD. Ninety percent of patients had moderate or severe disease requiring oxygenation. Moreover, 93.8% of patients were on antiviral drugs, 56.3% on immunosuppressant agents (baricitinib/tocilizumab), and 75% were taking dexamethasone. The average time to pneumothorax onset was 22.0 days. Bilateral pneumothorax and pneumomediastinum was noted in one patient each. Chest drainage was performed in 68.8% of patients. Mean treatment duration for pneumothorax was 14.4 days and the 30-day mortality rate was 25.0%.

Conclusion: Pneumothorax associated with COVID-19 was more common in patients with moderate or severe disease requiring oxygenation and had high 30-day mortality rate. Clinicians should pay attention to it.