Another thing connected to dermographism is angioedema.

Here are some links:
http://www.haea.org/

http://www.hcplive.com/publications/...-04/2005-04_02

HAE will also cause abdominal pain.
This is what I have been diagnosed recently with...and I have to
go to an immunologist soon (after my drug induced lupus and AE
simmer down from lisinopril), for further testing.

You can search for more yourself, as you read these two very good sites.

Angioedema often does not get diagnosed until a crisis, which is what I had, recently.

The HAE site gives the blood work needed, so your can pass that along to your doctors.

I didn't have itching so much as burning stinging. Also swelling of the affected areas.

So please do look at these two links.