I kind of doubt that's the problem, as I haven't got a single allergy, have never had asthma, have never had any sort of autoimmune disease or inappropriate inflammatory response at all... I don't even have dry skin. A systemic problem would show itself in multiple sites, most likely.

I've never smoked and don't plan to start. I don't like the smell. They did ask me that when I got the birth control pills, since they say smoking is a risk factor for unacceptably high blood pressure and a resulting stroke. (That would be the aneurysm kind of stroke, not the clotting sort.)