title: Dermographism (mechanical urticaria) mediated by IgM.
abstract: Sera of three patients with symptomatic mechanical urticaria caused an immediate weal and flare reaction when injected intracutaneously into related recipients, and serum of one patient caused the same reaction in his own skin. Pretreatment of test skin sites with Compound 48/80 abolished or greatly reduced the reaction. This weal-producing substance was found in the same fraction as IgM in Sephadex G-200 gel filtration, was stable to heat treatment (56 degrees C, 4 h) and labile to 2-mercaptoethanol treatment. An immunoadsorption study using anti-IgM serum identified this weal-producing substance as IgM.
mesh_terms: D000293:Adolescent; D000328:Adult; D002850:Chromatography, Gel; D005260:Female; D006358:Hot Temperature; D006801:Humans; D007075:Immunoglobulin M / Q000032:analysis*; D007163:Immunosorbent Techniques; D007428:Intradermal Tests; D008297:Male; D008623:Mercaptoethanol; D011312:Pressure; D014581:Urticaria / Q000276:immunology*; D003189:p-Methoxy-N-methylphenethylamine
chemical_list: D007075:Immunoglobulin M; D003189:p-Methoxy-N-methylphenethylamine; D008623:Mercaptoethanol