Pseudomonas aeruginosa as an unusual cause of cavitating lung lesion

A 31-year-old woman with systemic lupus erythematosus presented to the emergency department with cough for 1 week. Chest radiograph demonstrated cavitating lesion in the right upper zone with surrounding ground-glass change. Blood culture results from the day of hospital presentation grew Pseudomonas aeruginosa . Sputum sample and pleural fluid grew P. aeruginosa and were negative for acid-fast bacilli. P. aeruginosa is a rare cause of cavitating lung lesion and has been associated with immunocompromised hosts. Most reports of cavitating P. aeruginosa lesions have been identified in patients who are immunocompromised secondary to HIV.The current case highlights the potential for infection in patients who are immunosuppressed therapeutically and appropriate investigations are necessary to rule out common causes of cavitating lung lesions.