Prediction of late asthmatic responses to inhaled allergen.

Relationships between cutaneous and bronchial responses to allergen were examined in nineteen atopic asthmatics. Allergen inhalation tests elicited an isolated early asthmatic response (EAR) in ten subjects and a dual asthmatic response (DAR) in nine subjects. Ragweed IgE RAST, performed with the sera of those patients tested with ragweed antigen, yielded higher values in all but one patient who experienced DAR than any of the patients with EAR. In one patient with annual symptoms in the ragweed season, positive skin tests with ragweed antigen and DAR to inhaled ragweed extracts, the IgE RAST was entirely negative and the serum IgE concentration was low. Dilutions of the allergen used in each individual for inhalation were also used in skin-prick tests. Early cutaneous allergic response (ECAR) mean wheal diameters were obtained at 10 min and late cutaneous allergic response (LCAR) mean diameters at 6-8 hr. Early asthmatic response (EAR) subjects differed modestly from DAR subjects in the relationships between ECAR and LCAR; in the EAR group, a significantly larger wheal diameter (P less than 0.01) was required before an LCAR ensued, however there was some overlap. Once LCAR developed, there was no difference between EAR and DAR groups in the magnitude of the LCAR. There was a trend (not significant) towards a requirement for a higher antigen concentration in the EAR group to elicit an LCAR.(ABSTRACT TRUNCATED AT 250 WORDS)