[Histamine as a mediator of allergic inflammation]

The allergic process is believed to consist of two phases: early and late. The early phase reaction is mainly induced by histamine released from mast cells. Histamine binding specific cell receptors produces clinical allergic symptoms. This mediator also activates neutrophils and eosinophils as well as being a chemoattractant for these cells. Histamine increases IL-8 level and evokes leukocyte rolling on endothelial cells. Thus histamine participates in both early and late-phase allergic responses.