'Flare' in Triple response is mediated by
Lewis Triple response includes wheal, flare and red reaction.
Histamine when released causes capillary dilatation due to precapillary sphincter relaxation resulting in red reaction. Due to the dilatation, the gap between endothelial cells is widened, which leads to increased permeability and allows extravasation of fluid resulting in wheal. Axon reflex mediates arteriolar dilatation resulting in flare.
Axon reflex
Arteriolar dilation
Histamine release
Local hormones