Clinical characteristics of childhood asthmatics in Johannesburg.

OBJECTIVES: To describe the clinical features of Caucasian childhood asthmatics in Johannesburg in order to compare these with a similar population of black asthmatic children resident in Soweto.
DESIGN: In a prospective study, a history was obtained by means of an investigator-administered questionnaire. MAIN OUTCOME MEASURES: Presenting asthma symptoms, precipitants of symptoms, concomitant diagnoses, individual and family background of allergy and 'delay to diagnosis' of asthma (age at symptom onset subtracted from age at diagnosis) from history and allergen sensitivity as assessed by skin-prick tests (SPTs).
RESULTS: Of the 468 (297 boys) asthmatics studied, 456 (97.4%) presented with cough, 362 (77.3%) with wheeze, 286 (61.1%) with a tight chest and 277 (59.2%) with breathlessness. Cough as sole symptom occurred in 102 (21.8%) while only 8 (1.7%) wheezed and did not cough. Commonest symptom triggers were upper respiratory tract infections and activity/exercise. An individual atopic background was common-allergic rhinitis in 413 (88.2%)-as was a family history of atopy, present in 390 (83.3%). Prolonged symptomatic periods occurred in most patients before asthma was diagnosed (among children diagnosed after the age of 4 years, 50% had been symptomatic for more than 3 years). 'Delay to diagnosis' was not influenced by presenting symptoms or by previous hospitalisation for asthma. Other respiratory diagnoses of bronchitis and pneumonia were common, possibly because of misdiagnosis. Commonest allergens on SPT were corn pollen, Bermuda and 5-grass mix, and standardised mites. Aside from wheat, food allergy was uncommon.
CONCLUSIONS: Cough was the commonest presenting symptom despite its still being regarded as a less classic symptom of asthma that may account for misdiagnosis and a high frequency of other respiratory diagnoses. Associated allergy, especially allergic rhinitis, occurred frequently. Many aspects of presentation in whites were similar to those in Soweto children, although the latter had a more frequent concomitant diagnosis of tuberculosis, and recognised dust and cold weather as more frequent triggers. Differences might be influenced by the care-giving situation.