[Acute and chronic bronchitis].

Acute bronchitis and exacerbations of chronic bronchitis are important problems in clinical practice. Acute bronchitis is frequently caused by viruses, and rarely by Mycoplasma or Chlamydia pneumoniae. Antimicrobial therapy is generally not indicated. The causes of exacerbations in patients with chronic bronchitis are often not clear. Beside environmental irritants and hypersensitivity with acute bronchospasm, viral infections are important. The role of bacterial infections is not established. Nevertheless, early antibiotic treatment seems to be beneficial, particularly in reducing the incidence of respiratory deterioration, and therefore decreasing cost and morbidity.