People with asthma are not at an increased risk of having a common cold, but are more likely to develop more severe respiratory symptoms if infected with the cold virus, conclude authors of a UK study in this weeks issue of THE LANCET.
Rhinoviruses are the most frequent cause of the common cold. It has long been thought that people with asthma are more susceptible to colds than people without the disease. Jonathan Corne from Queens Medical Centre, Nottingham, UK, and colleagues did a study to investigate whether people with asthma are more susceptible to rhinoviruses, and to compare the effects of rhinovirus infection between people with or without asthma.
76 cohabiting couples were recruited to the study. One person in every couple had atopic asthma and the other did not. Participants completed daily diary cards of upper-respiratory-tract (URT) and lower-respiratory-tract (LRT) symptoms. They also measured their peak expiratory flow from the lungs twice daily. Nasal secretions were examined for rhinovirus every two weeks.
753 nasal samples were assessed. Rhinovirus was detected in around 10% (38/378) of samples from participants with asthma and 8.5% (32/375) of samples from healthy participants. However, after adjustment for confounding factors, asthma did not significantly increase the risk of infection. Rhinovirus infection was associated more frequently with LRT infection in participants with asthma than in healthy individuals (12 of 28 infections compared with four of 23). Symptoms of LRT associated with rhinovirus infection were substantially more severe and longer-lasting in participants with asthma than in healthy participants. The two groups did not differ in frequency, severity, or duration of URT infections or symptoms associated with rhinovirus infection.