Skin Reactions

The electrophoretic method of introducing certain allergens into the skin is a useful reproducible technique for transporting these allergens into the dermis. Giant ragweed, dwarf ragweed, and timothy extracts have been employed in this way. An electrophoretic unit of pollen dosage is defined. Giant and dwarf ragweed extracts have been used satisfactorily in the preseasonal treatment of a series of seven cases of hay fever by electrophoresis of the skin-reactive constituents. Analysis of undialyzed ragweed extract, using both the Philpot-Svensson and Longsworth techniques to estimate the amount of skin-reactive, unpigmented constituent present, has revealed that a very large amount of the unpigmented fraction is present in undialyzed extract of giant ragwee. We have, 7 therefore, been using undialyzed extracts in treatment experimentally since they are much simpler to prepare and less expensive. It is possible to introduce large quantities of skin-reactive material from undialyzed extracts by electrophoresis. Several patients treated preseasonally in this way in New York City have thus far (Aug. 27, 1940) had a satisfactory season.