Table 5 Risk factors for pneumothorax secondary to GPA

Active stage of Granulomatous vasculitis

19/20(95.0%)^a

Pulmonary nodules broke into the chest cavity

15

Pleural necrotizing granulomatous vasculitis

1/12 (8.3%)^b

Bronchial pleural fistula

2/12 (16.7%)^b

Lesions fibrosis with pleural cohesion

1/12 (8.3%)^b

Secondary infection in nodule cavity

3

Lesions fibrosis due to immunosuppressant

1

Delayed wound healing due to Glucocorticoid

2

Others

1