A wheal and flare reaction is characterized by which of the following?
1)Headache
2)Welt formation
3)Local redness
4)Fever
5)Local swelling

Question

Quizplus · Accepted Answer

Scraping a tongue depressor or blunt pencil across the sensitive skin of the inner arm can illustrate a local inflammatory reaction at least partly mediated by histamine.The result is a wheal and flare reaction,also called a triple response (local redness,welt formation,and a reddish white border).The redness and wheal (welt)are caused by dilation and leakage of plasma proteins from skin capillaries.The exudation of plasma causes the swelling.The flare,or reddish white area surrounding the wheal,is probably due to local axon reflexes from sensory fibers causing dilation of neighboring arterioles.

A Wheal and Flare Reaction Is Characterized by Which of the Following