Shifting percussion dullness of the chest: a sign of pleural effusion.

Early physicians diagnosed pleural effusion by detecting shifting percussion dullness of the chest. However, the lateral decubitus positions have not been routinely used to distinguish this condition from atelectasis or pneumonia. In this report, postural alterations of percussion dullness established the diagnosis of pleural effusion in a 49-year-old patient with a cough. Percussion in the lateral decubitus positions may enhance the value of examinations of the chest.