Empyema Necessitans: A Rare Complication of Chest Drains

Empyema is defined as an accumulation of frank pus within the pleural cavity. Empyema necessitans is a rare complication of the pleural space infection when the existing empyema extends into adjacent structures beyond the pleural space, usually into the soft tissue of the chest wall. If severe, it can externalize to the skin. Historically, one of the most common causes of this condition was uncontrolled tuberculous infections. Our study describes a case where empyema necessitans could be classed as iatrogenic. This patient was initially admitted for empyema secondary to community-acquired pneumonia, which was successfully treated with a course of antibiotics and insertion of a chest drain. She was discharged but had to be re-admitted after one month, this time with a chest wall swelling at the point of recent chest drain insertion, which began to ooze purulent discharge. Imaging confirmed the diagnosis of empyema necessitans, which was then treated with a combination of surgical and antimicrobial therapy. Empyema necessitans are now seldom encountered, owing mainly to effective antibiotics and anti-tuberculous treatment. It is perhaps even more rarely seen as a complication of chest drain insertion. However, the report emphasizes the need to consider empyema necessitates in the list of differentials when assessing a patient with chest wall swelling, particularly where they have recently undergone pleural intervention.