Stability of respiratory symptoms in unlabelled wheezy illness and nocturnal cough

To assess the natural history of respiratory symptoms not labelled as asthma in primary schoolchildren.

Repeat questionnaire survey of subgroups identified from a previous questionnaire survey after a two year delay.

The original population of 5321 Sheffield children aged 8-9 years yielded 4406 completed questionnaires in 1991(82.8%). After excluding children with a label of asthma, there were 370 children with current wheeze, 129 children with frequent nocturnal cough, and a random sample of 222 children with minor cough symptoms and 124 asymptomatic children.

Response rates in the four groups were 233 (63.0%), 77 (59.7%), 160 (72.1%), and 90 (72.6%) respectively. Of those who initially wheezed, 114 (48.9%) had stopped wheezing and 42 (18.0%) had been labelled as having asthma. Those with more frequent wheezing episodes (p < 0.02) and a personal history of hay fever (p < 0.01) in 1991 were more likely to retain their wheezy symptoms. In the children with frequent nocturnal cough in 1991, 20.1% had developed wheezing, 42.9% had a reduced frequency of nocturnal coughing, and 14.2% had stopped coughing altogether two years later. One sixth had been labelled as having asthma. Children with nocturnal cough were more likely to develop wheezing if they had a family history of atopy (p = 0.02). Only 3.8% and 3.3% of those with minimal cough and no symptoms respectively in 1991 had developed wheeze by 1993 (1.9% and 1.0% labelled as asthma).

Most unlabelled recurrent respiratory symptoms in 8-10 year olds tend to improve. Unlabelled children who have persistent symptoms have other features such as frequent wheezing attacks and a family or personal history of atopy. If a screening questionnaire were to be used to identify such children, a combination of questions should be employed.