Legend for Figure 1
Figure 1. Activation of the coagulation system in chronic
urticaria. Mast cells release inflammatory mediators including
histamine after degranulation leading to activation of endothelial cells
and eosinophils. Activated endothelial cells and eosinophils express
tissue factor initiating coagulation activation after binding to
activated factor VII (FVIIa) generating thrombin. Thrombin induces
activation of platelets, cleaves fibrinogen, recruits inflammatory
cells, activates mast cells and endothelial cells by binding to and
cleaving protease-activated receptor (PAR-1) leading to increased
vascular permeability with extravascular spillover of inflammatory
mediators. EOS, eosinophils; MC, mast cells; NEU, neutrophils; F1+2,
prothrombin fragment 1+2; FDP, fibrin degradation products; PL,
phospholipids.