Dermatographism - me too
I have dermatographia in addition to allergies and Benadryl at night sometimes helping the next day.
Hi Samuel, I developed dermatographism too, and have found massive relief with Doxepin first, then Amitriptyline (not widely recognized - it's also a powerful antihistamine). I've seen similar patient reports on dermatographism & Amitriptyline some of the chronic Parvovirus B19 forums. PVB19 symptoms are known to often be worse late winter/early spring, and my dermatographism has indeed tended to be worst then. At its worst, pre-diagnosis, I was getting 3-4 hours of sleep/night due to the horrendous itching. On one of the Parvovirus B19 forums one little kid with PVB19 was telling his mom he wanted to die, the itching was so bad. Insane crawling sensation especially on face, scalp for me. I actually got sent to a tropical diseases travel clinic, they thought I might have had parasites from my prior travels. If I miss a dose of Ami, I can't sleep from the itchiness. And interestingly each time my immunoglobulin levels are higher from my antibody therapy for the PVB19, my dermatographism/itching subsides too, and I am able to reduce my amitriptyline dose. In year 4 of this itchiness I finally found a competent dermatologist who did the skin-scratch test and pronounced it "dermographism or dermatographism". If you try this on yourself, better get a partner to scratch your back (literally). So much of our skin gets desensitized by touch and the back is an area that isn't as constantly overstimulated. So the "writing on skin" effect is more pronounced there, and you'll see your scratch mark turn red, then persist. (see pic below)
Ironically I thought my dermatologist was dead wrong when she first made the diagnosis, but I dutifully took the Doxepin she prescribed and was flabbergasted that I could sleep itch-free that very first night. The difference in the itchiness was literally night and day. And kind of like the reverse-placebo effect, because I was sure she was wrong

From my experience, both Doxepin, then Ami MUCH more effective antihistamines than Benadryl.
OK, this is cool. Downloaded from Wikipedia:
http://en.wikipedia.org/wiki/Dermatographic_urticaria
Dermatographic urticaria (also known as dermographism, dermatographism or "skin writing") is a skin disorder seen in 45% of the population and is one of the most common types of urticaria,[1] in which the skin becomes raised and inflamed when stroked or rubbed with a dull object.[2]
Presentation
The symptoms are thought to be caused by mast cells in the surface of the skin releasing histamines without the presence of antigens, due to the presence of a weak membrane surrounding the mast cells. The histamines released cause the skin to swell in the affected areas.
There are some really interesting crossovers with dermatographism and ME/CFS:
- Found in 4-5% of the population. This could be just coincidental of course, but might there be an XMRV link?
- Can be associated with antiphospholipid antibody syndrome, a known complication of viral infection, including parvovirus B19
- Can also be associated with Raynaud's phenomenon - another auto-immune vascular response known to be associated with chronic PVB19/ME/CFS.
- Also note some of the literature describes dermatographism as a cutaneous (skin) vascular response. And PVB19 is known to attack the endothelium (inner lining) of blood vessels.
- You can see more if you look up "parvovirus" ( or "virus") and antiphospholipid syndrome on the National Library of Medicine's PubMed search engine: http://www.ncbi.nlm.nih.gov/sites/entrez .