Morrison J G, Hull P R, Fourie E
Br J Dermatol. 1977 Jul;97(1):99-104. doi: 10.1111/j.1365-2133.1977.tb15435.x.
A mixed cryoglobulin (IgG/IgM) was detected in a patient with erythema elevatum diutinum. Cold exposure activated the complement system and provoked a fixed urticarial reaction with the histology of a leukocytoclastic vasculitis.