40 year-old male presents with fever, chills, & cough. What’s the diagnosis and the MOST likely cause?
Answer: Pneumatocele from MRSA pneumonia
Pneumatocele
Pneumatoceles are thin-walled, air-filled cysts with lung parenchyma; they may be solitary or multiple
Most commonly a sequellae to pneumonia secondary to Staphylococcus aureus (up to 85% of cases), although other etiologic agents have been found (Streptococcus pneumonia, E. coli, Klebsiella, Adenovirus and Tuberculosis). Non-infectious causes include trauma, hydrocarbon ingestion, and positive pressure ventilation.
Pneumatoceles are typically asymptomatic and require treatment of the inciting etiology (e.g., antibiotics for pneumonia), but complications may occur including tension pneumatocele, pneumothorax, and secondary infection of the pneumatocele.
Surgical resection is typically not needed but percutaneous catheter drainage may be required if the pneumatocele involves >50% of the hemithorax
Advise patients against exposure to high altitudes, skydiving and scuba diving until pneumatocele(s) resolve, to avoid progression to pneumothorax.
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