The words written on the patient’s back read ‘Démence précoce’ (Dementia praecox). In fact, the woman is likely to have dermatographic urticaria or dermographism, a condition in which the skin becomes inflamed or raised when scratched or rubbed, producing visible marks; a condition that affects a small but significant number of people.
At the time that the picture was taken, at the Salpêtrière hospital in Paris, there was a mistaken belief that this phenomenon of ‘skin writing’ was a manifestation of a psychological disorder; hence the diagnosis of dementia praecox, a psychotic disorder. In fact the condition is caused by a weakness in the membranes around mast cells in the skin, causing them to release histamines, in a similar fashion to an allergic reaction.
If diagnosis and understanding have improved, the habit of demonstrating the diagnosis by writing on the back persists, as you can see in this informational page about the condition. Others take a more creative approach. Australian artist Ariana Page Russell, who has the condition uses her own skin as a canvas.
But our attention has really been caught by the members of the Dermatographic Urticaria Flickr group. A relatively small group of people use the photo-sharing website to show the temporary marks they’ve made on their skin which range from political declarations and protest, through intricate patterns to illustration, combination with tattoos and artistic impressions of the condition.
It’s a remarkable example not only of how far both medical understanding and photographic technology have come, but also of how the internet can bring together people from around the world to share not only their personal experiences of a medical condition, their highs and lows, but also their own extraordinary creativity.