You can't just be a carrier for EHK because its a dominant condition - as is vulgaris. If you have the gene you will have the symptoms. That also means there is a 50/50 chance of passing it to your child. The gene causing EHK is known so you can check for it when you are pregnant, but only a few of the genes causing vulgaris are known so you are unlikely to be able to check for that.
I was reading the FIRST website recently and there was an article on vulgaris (http://www.scalyskin.org/content.cfm?ContentID=260&ColumnID=4
) saying that vulgaris is actually semi-dominant. So if your partner also has vulgaris then your child could have a bad case. If your partner doesn't have it then your child should have it the same severity as you.