Terbutaline modulation of human allergic skin reactions

Terbutaline, a preferential beta₂-adrenergic agonist, has been shown to inhibit allergen-induced histamine release in vitro. In contrast, orally administered therapeutic doses of terbutaline do not inhibit antigen-induced wheal and flare reactions. We studied the effects of local terbutaline on antigen-induced whealing response, histamine release, cellular inflammatory response, and ultramicroscopic mast cell changes in antigen-challenged skin sites in ragweed-sensitive subjects. Results showed that ragweed challenge significantly induced increased histamine release in all subjects. In contrast, no such histamine release was observed at sites challenged with antigen in the presence of terbutaline. Thus locally applied terbutaline in nontoxic doses modulates mediator release in certain allergic reactions.