Have you ever heard if dermatographism in any way shape or form is related to hormones in a woman's body?
The cause is often difficult to isolate and sometimes impossible. It may have been something than happened to you a couple of months ago.
Hormones, illnesses affecting the glands, and drugs (including oral contraceptives) are thought to possibly play a role in dermatographism. Myself I did see an endocrinologist at one point because I was getting hot flushing of the skin. This was before I developed dermatographism. Testing showed no problems however.
A visit to the dermatologist and your family physician is a good idea. It is important to rule out other illnesses which may be causing the dermatographism. If there is no underlying cause then the dermatologist will try some different antihistamines to try and relieve (not cure) the symptoms. In most cases you will find a drug that will help. However, if you are planning to have a child then I would be careful of what is being prescribed because treatment with antihistamines may be for several months at a time.