Last updated: Sun, Jun 18, 2017
The first thing you may notice is a sharp pain that clearly comes from the location of the scratch. In other words, the pain is clearly localized. This first message is the result of action potentials fired by A-delta fibers along the length of the scratch. Depending on how long the injury takes, and depending on where on your body it occurs, you may feel another, second pain shortly after the first. The second message is the result of the firing of C fibers. If you feel the second pain, you may notice that it is not as clearly localized nor as sharp as the first pain.
The next thing you may notice is that the skin surrounding the scratch turns white. This is because the smallest arteries near the skin were stretched when you were scratched. When they are stretched, they go into spasm and don't permit blood to flow. This is an automatic local response to prevent blood loss, in case your tissue is torn.