Skin-prick test reactions to inhalant allergens in asthmatic patients

Skin-prick tests with extracts of a large number of inhalant allergens were carried out on 489 asthmatic patients attending the thoracic outpatient clinics at two Sydney hospitals. Positive reactions, which had been previously found to be invariably accompanied by bronchial immediate allergic reactivity, occurred in 98% of patients who had had symptoms of asthma since the first decade of life, and in 28% of those whose symptoms did not begin until after the age of 60 years. Prick-test reactions were most commonly produced by house dust and house dust mite (70%), followed by grass pollens (50%), moulds (30%), weed pollens (35%) and tree pollens (22%). The patients commonly gave positive reactions to two or more of the extracts from within each of those allergen groups.