title: Protean manifestations of pleural empyema caused by Streptococcus pneumoniae in adults.
abstract: BACKGROUND
  The aim of this study was to describe the clinical characteristics of pleural empyema caused by Streptococcus pneumoniae.
  
  
  METHODS
  A retrospective cohort analysis was conducted at the University Hospital 12 de Octubre, Madrid (Spain). We included all adult patients with pleural empyema caused by S. pneumoniae diagnosed from 1998 to 2004.
  
  
  RESULTS
  Eighteen cases of pleural empyema due to S. pneumoniae were analyzed. Fourteen patients had symptoms of respiratory infection, three had other symptoms, and one patient was asymptomatic. One-third of the patients did not have a pneumonia infiltrate visible on chest radiogram. In 46%, bacteremia was detected. All pleural fluids had a high white blood cell count, either with polymorphonuclear or lymphocytic predominance. Drainage with a chest tube was used in 94.4% of cases. Nine patients had a favorable outcome, five had to be admitted to the intensive care unit, and two died within the first week (mortality rate of 11.1%).
  
  
  CONCLUSIONS
  Pleural empyema caused by S. pneumoniae has to be considered an aggressive disease that, occasionally, affects young and previously healthy individuals. Clinical manifestations are variable and pleural fluid can be a lymphocytic exudate. It has a noticeable associated morbidity and mortality, which must be kept in mind by clinicians when approaching a patient with a pleural effusion.
authors.affiliation: Department of Internal Medicine, University Hospital 12 de Octubre, Avda, de Córdoba s/n, 28041 Madrid, Spain.
authors.forename: María José
authors.initials: MJ
authors.lastname: Fernández-Cotarelo
authors.forename: Francisco
authors.initials: F
authors.lastname: López-Medrano
authors.forename: Rafael
authors.initials: R
authors.lastname: San Juan
authors.forename: Carmen
authors.initials: C
authors.lastname: Díaz-Pedroche
authors.forename: Manuel
authors.initials: M
authors.lastname: Lizasoain
authors.forename: Fernando
authors.initials: F
authors.lastname: Chaves
authors.forename: José María
authors.initials: JM
authors.lastname: Aguado