You become the paper with "skin writing". With “skin writing” you never get caught short without a pen, as this peculiar condition makes it possible to write messages on human skin with the touch of a finger. Known as dermatographic urticaria, it’s estimated to affect around 2 to 3 percent of the population. Dermatographism, as the condition is known, literally means “to write on the skin” and that’s precisely what it allows you to do. It’s characterized by an “urticarial eruption” when pressure is applied to the skin, showing up as a red, inflamed mark that looks a bit like a burn or scar. It affects a small number of people, typically young adults, but can occur at any age and for a myriad of reasons including other illnesses like scabies, or the use of certain medications. As for the mechanism behind it, this also isn’t exactly clear but histamine may well play a part. Histamine is a compound that’s released by our cells when they’re injured, inflamed, or experiencing an allergic reaction. That’s why the redness and swelling you get around a fresh scratch looks similar to that you get from touching a stinging nettle, or something very hot. Histamines respond to undesirable triggers, but sometimes they can overreact. This is why some people take antihistamines to dampen their allergy symptoms, which can be triggered by innocent things like pollen or pet dander. This ties into dermatographism because it’s possible skin writing is caused by touch triggering a chain reaction that results in the release of histamine, in the same way as other irritants and allergens. This leads to swelling, redness, and sometimes itching. Because the touch needed to trigger skin writing is so light, this peculiar condition can significantly impact someone’s quality of life despite not being particularly dangerous. The welts appear quickly and can endure for several hours, making it easy to be left with noticeable marks that may affect a person’s confidence. In most cases dermatographism doesn’t last forever, but it can linger on for months or even years. Skin writing triggered by a previous illness like scabies tends to dissipate faster; meanwhile, dermatographism that takes longer to appear after touch is associated with a longer course of the condition. Skin is often overlooked as the body’s largest organ, but it’s constantly doing weird and wonderful things. Did you know that all of us have invisible zebra stripes called “lines of Blaschko”? Source
