This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
'Flare' in Triple response is mediated by 
Select and explain. 
A. Axon reflex, B. Arteriolar dilation, C. Histamine release, D. Local hormones
A: Axon reflex
Answer: A: Axon reflex 
Explanation: 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.