Nonpneumonic Legionnaires' disease [Pontiac fever]

This code represents Pontiac fever, a mild, self-limiting, non-pneumonic form of Legionellosis. It is characterized by a flu-like illness without evidence of pneumonia or other severe systemic involvement. Symptoms typically include fever, headache, myalgia, and malaise.

Use this code when documentation clearly indicates a diagnosis of Pontiac fever, confirmed by laboratory testing (e.g., positive Legionella antigen in urine or serology) or strong epidemiological links, and the absence of pneumonia. This code is appropriate for patients presenting with acute febrile illness consistent with Pontiac fever who do not develop respiratory compromise.

• Differentiate carefully from Legionnaires' disease (pneumonic form), which is coded elsewhere.
• Ensure documentation explicitly states "Pontiac fever" or "nonpneumonic Legionnaires' disease."
• Do not use this code if the patient develops pneumonia, even if Legionella is the causative agent.