Dr. Maha talal
DefinitionTriple response: normal physiological responce of skin to physical , chemical or mechanical truma that will not cause distruction to the integrity of skin. It is a protective mechanism.
Events of Triple response
Flushing (redness): appear after 10 sec . Flare (irregular area of redness): due to arteriolar dilation Wheal (local swelling): few minutes at the area of capillary dilation .Components of triple response
Direct action of histamine: capillary dilation ( flush and wheal) Indirect action: arteriolar dilation (flare and itching).Operation of the axon reflex
Mechanism of action
arterioleskin
Orthodromic impulse
Antidromic impulse
histamine