Pneumonia in whooping cough

This code signifies the presence of pneumonia that has developed as a complication of pertussis, commonly known as whooping cough. It indicates a bacterial lung infection occurring secondary to the primary pertussis infection, often characterized by inflammation of the lung parenchyma.

Apply this code when documentation clearly states a diagnosis of pneumonia arising in a patient with confirmed or suspected whooping cough. This typically occurs in infants and young children, but can affect individuals of any age. Supporting documentation would include physician notes detailing both pertussis and a concurrent pneumonia.

• Always code the underlying pertussis (033.0-033.9) first, followed by this code for the pneumonia.
• Specify the type of pneumonia if documented (e.g., bacterial, viral) using an additional code if applicable, though 484.3 inherently implies a bacterial etiology in the context of pertussis.
• Do not use this code for pneumonia from other causes, even if the patient has a history of pertussis; the pneumonia must be a direct complication.