Inhibition of axon reflex vasodilatation by topically applied capsaicin

Topical application of capsaicin to human skin produced an initial burning erythematous reaction which diminished over 24 hr leaving the skin unresponsive to histamine-induced axon reflex vasodilatation without altering sensitivity to pain, touch and temperature. Depletion of substance P from local sensory nerve terminals is suggested as a possible explanation for this capsaicin effect.