The sudden appearance of pneumothorax in a child suffering from pneumonia points to which etiology?

Pneumonia caused by S. aureus may be primary or secondary after a viral infection such as influenza. Common symptoms and signs include high fever, abdominal pain, tachypnea, dyspnea, and localized or diffuse bronchopneumonia or lobar disease. S. aureus often causes a necrotizing pneumonitis that may be associated with early development of empyema, pneumatoceles, pyopneumothorax, and bronchopleural fistulas.Ref: Nelson Textbook of Paediatrics; 20th edition; Chapter 181; Staphylococcus