I randomly got rather itchy a few months ago, and just figured it was dry skin. Lotions and special, moisturizing baths didn't help. After a while, I noticed my skin would puff up where I'd scratch. Thought it was kind of odd. I was finally able to figure out what I have through google.

I have what is called "dermographism" or "dermatographism" (also known as "skin writing") and it apparently only affects 2% - 5% of the population.

To read more about it, check out the wikipedia article which explains it quite nicely: [link]

Here are some webcam pictures I took of mine. This is "written" gently with a letter opener on my forearm. It would almost be cool if it weren't so annoying.




I didn't have to scratch very hard. Moderate pressure is enough to cause the reaction. It can be a dull or sharp object, it doesn't matter. It's the pressure that causes the cell membrane to burst, which in turn causes an allergic reaction, because the burst cells release histamines, or something like that. For me, It takes about five minutes to appear in full force and around 15-20 to go fully away. I believe there are things to treat it, but no cure. The problem becomes that the skin itches normally, which is fine until I scratch. Then, when I scratch, I burst the cell membranes, which causes a minor, local allergic reaction, which then itches more, causing me to scratch more. Right now, it's not severe enough to go to the doctor, but at least I know what it is if I do need to.

Despite all that, it's still actually rather intriguing.