Scratch Test for Histamine-Positive Skin

What is the scratch test you mentioned in a previous post?

I refer to the test as one used to discover a histamine positive skin type. The simple test is done by scratching the skin with a finger nail (for example) with moderate pressure, but not enough to cut into the skin. The skin will develop a red-streak within a minute surrounding the finger nail scratch. This, I believe, is local release of vasodilators at the skin edge. I have noted in my practice that people who react to the scratch with a red streak are the ones who tend to remain more pink after a hair transplant. When I transplant these patients, I will often use copper peptide dressing, which I have found gets the pink out sooner in these patients. I have had patients who were positive to the scratch test who were not treated after their first surgery and then when I did their surgery a second or third time, the addition of (1) copper peptide dressings after surgery and (2) the use of high dose steroids at surgery has helped minimize the pink discoloration over time. My view of copper peptide is not shared by many doctors, suggesting that what I observed have not been their observations and their experience.