Skin Writing

I just found out the name for something I’ve seen in my son for a few years now. He has dermagraphia, also known as “skin writing”. If you lightly scratch or rub a spot on his skin, many times a dramatic welt will rise in that spot. It lasts about ten minutes or so, then fades away. It’s caused by cells in the surface of the skin releasing histamines, causing localized skin swelling.

It’s not harmful, but the poor little boy is always complaining about being itchy - and of course when he scratches the spot it just gets worse. Often after the swelling fades you’ll see little spots where his scratching has broken the skin.

It can be mildly alarming. If he has trouble tugging off a shirt that has a tight neck, for example, his face might be covered in welts for a while afterwards. We’ve had the school call us because he has turned up covered in welts after playing outside.

He’s already on Singulair for mild asthma, now we’re about to try Clarinex to see if that helps.

That does sound frightening. Just this morning I had an itch on my foot and when I scratched it the skin ripped open. That happens to me all the time. I keep my fingernails cut very short because I thought I was scratching too hard or something but I always get these welts and open places wherever I scratch.
It’s scary enough when it happens to me (I keep waiting to scratch really hard and have a leg fall off or something) but I can’t imagine seeing my little boy with welts.
Good that you have a diagnosis, though!

I didn’t realize there was a name for it. Years ago, I got a horrid chigger infestation. I was covered. A byproduct was the welts like you mention, just scratch the skin with a fingernail and instant welt would appear, about the “consistancy” of a mosquito bite but in any shape you wanted. Mine went away, thank goodness, hopefully some antihistamines will help your son.

Have you tried loratidine (AKA claritin)? I discovered this summer that it prevents poison ivy rash and stops the reaction to mosquito bites. Both of those, IIRC (and immunology class was a while ago), are immune reactions similar to what you describe. There is also cromolyn sodium that prevents mast cells from releasing histamines, however cromolyn sodium also has some unpleasant side-effects. As always, discuss these with the pediatrician/allergist before giving them to your son.


The doctor prescribed Clarinex, which he said was the good half of Claritin.

I took pictures! This is from his attempt to write his name on one arm and his brother’s name on the other. It’s really weird. He scratched gently with a fingernail, and for a minute there was no sign of anything, then the welts appeared. A few minutes later they were gone.

My best friend when I was growing up had this. Any little scrape would swell up, then fade away. Freaky!

My husband gets welts like that just from leaning on the back of a chair, or sometimes from a wrinkle in the sheet. Only on his back, though. The rest of him must be tougher, and it’s definitely hairier. Maybe that protects him. He gets welts the size of a quarter from mosquito bites, but they don’t itch and they’re gone in about fifteen minutes.

I had this as a child! I never knew it had a name. Consider my ignorance fought. :slight_smile: