What is it?
Also called “skin writing”, where friction (scratching or some other contact) causes red hives or raised skin.
Likely an overabundance of histamine in the body. Some possibilities might be mast cell activation syndrome (MCAS), environmental allergens, mild chronic food issues, high histamine foods, histamine releasing foods, or body does not break down histamine well due to lack of enzymes such as diamine oxidase?
Ways to control?
Aside from antihistamines, our allergist at the time recommended better control of environmental factors such as dust mite control and removing fragrance. Also to avoid tomatoes and berries (histamine releasing foods?).
My partner’s dermatographism disappeared along with our diet experiments but at the same time we started better management for environmental allergens as well, so it is not clear what was the main culprit. Regardless this didn’t come back except for a brief return during travel when we had much more fermented foods and was in a dusty environment. So again, not sure which is the cause, or perhaps it is both.