Effect of respiratory infections on exacerbation of asthma in adult patients. A six-month follow-up.

The peak expiratory flow values and asthma symptom scores of 92 adults with extrinsic and intrinsic asthma were recorded daily from September 1981 to April 1982 in order to study the effects of symptomatic respiratory infections (SRI) on the course of asthma. During the follow-up, 253 exacerbations of asthma were observed in 67 patients. 68 subjects had 141 episodes of SRI. 63 of 253 exacerbations (25%) were found in association with SRI. The mean duration of the exacerbations associated with SRI was 11.4 days, significantly different (P less than 0.01) from the mean duration of 8.1 days recorded for the other exacerbations. The results confirm the high incidence of asthmatic exacerbations during respiratory infections and suggest that the recovery from an exacerbation is slower in association with infection.