Legionnaires' disease and pneumonia. Beware the temptation to underestimate this "exotic" cause of infection.

Legionnaires' disease is an often overlooked but common cause of community-acquired pneumonia. The clinical presentation is nonspecific, although fever higher than 39 degrees C (102.2 degrees F), gastrointestinal symptoms, and hyponatremia should raise the index of suspicion. In this article, Drs Akbas and Yu describe specialized laboratory tests needed for definitive diagnosis and discuss therapeutic options.