In Lewis Triple Response, redness when skin is scratched with a pointed object is seen due to
Ans. b. Histamine release due to local injury to mast cells In Lewis Triple Response, redness when skin is scratched with a pointed object is seen due to histamine release due to local injury to mast cells Lewis Triple Response Lewis triple response is a three-pa response to blunt injury. It consists of the red reaction, wheal and flare. Lewis Triple Response Red reaction Red reaction appears at the site of injury within 10 secondsdeg. Due to dilation of pre- capillary sphincters by histamine and polypep aged skiff,. Wheal Wheal is local edema due to increased permeability of the capillaries with conse- quent extravasation of fluiddeg Occurs due to histamine or histamine-like substances released from local mast cellsdeg. Flare response Flare response is a spread? ing redness is due to ae? riolar dilatation produced by the axon reflee
Axon reflex causing vasoconstriction
Histamine release due to local injury to mast cells
Free nerve endings injury
Endothelial damage leading to increase in permeability