axon flare, vasodilation, reddening, and increased sensitivity of the skin surrounding an injured area, caused by an axon reflex. It is considered part of a triple response in which injury or stroking of the skin results in local reddening, the release of histamine or a histamine-like substance, a surrounding flare, and wheal formation. A pinprick in the involved area causes more intense pain than a similar stimulus before injury.
