Substance P antagonist inhibits immediate and delayed type cutaneous hypersensitivity reactions

The role of substance P (SP) in allergic reactions of the skin was investigated. Spantide, a competitive inhibitor of SP, was injected intracutaneously into the volar aspect of the forearm prior to the following challenges: benzalkonium chloride (irritant delayed reaction), tuberculin (immunological delayed reaction), UVB irradiation, benzoic acid (non-immunological contact urticaria), different food allergens and latex (in patients with immunological contact urticaria). Only the immunological reactions of contact urticaria and the reaction to tuberculin were suppressed by the SP antagonist, indicating that SP is involved in their pathogenesis.