Weird skin condition used for art

Have you heard about a skin condition referred as "dermatographia"? This is a condition in which one’s immune system exhibits hypersensitivity, via skin, that releases excessive amounts of histamine, which leads capillaries to dilate and welts to appear (lasting about half an hour) when the skin’s surface is lightly scratched. Artist Ariana Page Russell has this skin condition which frequently blushes and swells. This allows her to painlessly draw patterns and words on her skin, which she then photograph.

Here are a few samples: