RETICULATE PURPURA, CRYOGLOBULINEMIA AND LIVEDO-RETICULARIS

Two patients with type I cryoglobulinaemia are described, both of whom presented with purpura in a reticulate distribution on the legs, rese mbling the pattern of physiological livedo. It appeared that increased cooling due to sluggish blood flow in areas of the skin corresponding to the blue areas of physiological livedo may have caused the localiz ation of cryoprecipitate at these sites. To investigate the pathogenes is of the net-like pattern of purpura, three subjects with physiologic al livedo reticularis of the thighs were studied with a laser-Doppler velocimeter. In two subjects, mean blood flux in the blue areas was 21 % (P<0.01) and 26% (P<0.02) lower than in adjacent white areas, wherea s in the third there was no significant difference. The cutaneous feat ures of cryoglobulinaemia, and the mechanism of the reticulate purpura in this condition, are discussed.