Sputum in asthma.
A detailed questionnaire concerning sputum production was completed by 130 patients with variable airflow limitation fulfilling conventional criteria for asthma. The mean age at onset was 17 years and 75% had positive prick skin tests. One hundred of 130 (79%) reported sputum production; 21% were non secretors. In 68% of those with sputum it was a constant feature from the onset. Increased volumes of sputum was associated with more severe asthma and disability and negative skin tests. An additional component of persisting airflow limitation was found more frequently in the group characterized by no sputum and large volumes. It was less common in those with small sputum volumes. Irrespective of volume, 43% of 130 fulfilled the conventional criteria for MRC chronic bronchitis but 57% of these were non-smokers. We conclude that asthma and chronic bronchitis are not mutually exclusive diagnoses; a history of regular sputum production may lead to the underdiagnosis of asthma and its consequent under-treatment.
Cardiothoracic Institute, London, UK.
M
M
Turner-Warwick
P
P
Openshaw
D000293:Adolescent; D000328:Adult; D001249:Asthma / Q000150:complications / Q000175:diagnosis / Q000378:metabolism*; D001991:Bronchitis / Q000150:complications / Q000175:diagnosis; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012123:Pulmonary Ventilation; D012907:Smoking; D013183:Sputum / Q000378:metabolism*