Pneumococcal pneumonia—the most common serious pneumococcal syndrome—is difficult to distinguish from pneumonia of other etiologies on the basis of clinical findings.

• Pts often present with fever, abrupt-onset cough and dyspnea, and sputum production.
  • - Pts may also have pleuritic chest pain, shaking chills, or myalgias.
  • - Among the elderly, presenting signs and symptoms may be less specific, with confusion and malaise but without fever or cough.
• On physical examination, adults may have tachypnea (>30 breaths/min) and tachycardia, crackles on chest auscultation, and dullness to percussion of the chest in areas of consolidation.
  • - In some cases, hypotension, bronchial breathing, a pleural rub, or cyanosis may be present.
  • - Upper abdominal pain may be present if the diaphragmatic pleura is involved.
• Pneumococcal pneumonia is generally diagnosed by Gram's staining and culture of sputum.
  • - While culture results are awaited, chest x-rays—which classically demonstrate lobar or segmental consolidation—may provide some adjunctive evidence, although they may be normal early in the course of illness or with dehydration.
  • - Blood cultures are positive for pneumococci in <30% of cases.
  • - Leukocytosis (>15,000/µL) is common; leukopenia is documented in <10% of cases and is associated with a fatal outcome.
  • - A positive pneumococcal urinary antigen test has a high predictive value among adults, in whom the prevalence of nasopharyngeal colonization is low.
• Empyema occurs in <5% of cases and should be considered when a pleural effusion is accompanied by fever and leukocytosis after 4-5 days of appropriate antibiotic therapy. Pleural fluid with frank pus, bacteria, or a pH of ≤7.1 indicates empyema and requires aggressive drainage.