ABSTRACT
Exacerbations of chronic obstructive pulmonary disease (COPD) are a major cause of morbidity and mortality worldwide and have important consequences for patients and health care providers. They are predominantly triggered by infection and viruses are thought to be an increasingly important cause, with up to 64% of exacerbations associated with symptomatic colds (Fig. 1). The presence of cold symptoms at exacerbation increases the severity of an exacerbation, lengthens the recovery time (1) (Fig. 2), and in polymerase chain reaction (PCR)-confirmed colds, is associated with higher levels of airway inflammatory markers (2).
