| Abstract: | Ten healthy volunteers (five atopic, five nonatopic) and seven patients suffering from allergic bronchial asthma and rhinitis/conjunctivitis as well as showing dual reactions after intradermal or bronchial allergen challenge were investigated. Using the suction blister technique, we obtained skin-blister fluid (SBF) from dual skin reactions 30, 60, 180, and 300 min after allergen injection and from normal untested skin. The biologic activity of SBF was tested by intradermal reinjection of the fluid into the donor. SBF taken from dual skin reactions 30 or 60 min after allergen injection produced late cutaneous reactions (LCRs) quite similar to those induced by the allergen. SBF taken from LCR areas 180 or 300 min after antigen testing had much weaker effects, similar to SBF from untested skin. A possible content of allergen extract in SBF from allergen-tested skin areas was not responsible for the observed effects as demonstrated in passive cutaneous anaphylaxis experiments in monkeys. High doses of SBF from untested skin were able to induce LCRs similar to but weaker than LCRs produced by SBF taken at early phases from dual skin reactions. Similar volumes of autologous heparin-plasma or serum did not induce LCRs. It is concluded that during the initial phase of dual skin reactions, factors are formed that are able to induce LCRs. The generation of these mediators seems to be caused at least in part by the extravasation of plasma. |
