Varicella pneumonia

This code signifies pneumonia caused by the varicella-zoster virus, commonly known as chickenpox. It represents a severe complication of varicella infection, characterized by inflammation of the lung tissue.

Apply this code when documentation clearly indicates a diagnosis of pneumonia directly attributed to the varicella virus. This typically occurs in patients with a history of recent chickenpox infection or reactivation of the virus, presenting with respiratory symptoms and radiographic evidence of pneumonia.

• Ensure the documentation explicitly links the pneumonia to varicella; do not assume causation.
• Code the underlying varicella infection (B01.0-B01.9) as the primary diagnosis if it is the reason for the encounter, with this code as a secondary diagnosis.
• Distinguish from other viral pneumonias (J12.-) or bacterial pneumonias (J13-J18) which are not caused by varicella.