Abstract
Following bronchial provocation tests with inhalent allergens, late asthmatic reactions (LAR) frequently follow immediate asthma reactions (IAR). A study of atopic asthmatic children demonstrated that patients could show IAR to 1 allergen, ryegrass extract, but isolated LAR without any preceding immediate response when challenged with an unrelated allergen extract of Dermatophagoides pteronyssinus. The patients'' degree of skin sensitivity to the concentration of extract inhaled appeared one factor which determined whether an isolated LAR or IAR followed allergen inhalation.