I know your question about the headstand was posted in 2007, but just wanted to say I have recently experienced the same thing. I have a feet-up stool which takes all the weight on my shoulders and lets my head and neck hang freely. I used it a lot last summer with no adverse effects, but got it out again about 6 weeks ago and like you I had burst blood vessels like red pin pricks /freckles all around my forehead and the sides of my face and some around my eyes. I am otherwise fit, in my 40s. The rash faded in a week and I wasn't sure it was the head stand that caused it. But I used the stool again yesterday and the same thing happened. Very frustrating as I like to use the stool to free up my neck. Did you, or anyone else, find out the cause or cure for this strange phenomenon? ( I don't have high blood pressure or dark circles around my eyes though I did get an optical migraine 6 months ago following the NHS replacing my contraceptive pill with a cheaper version which I stopped taking).