It looks like a histamine reaction to me.
There might have been a impurity in the cut that you had an allergic reaction too.
Do you have any allergies?
.
I'm thinking the same, or that it's some kind of allergic reaction. Guido could certainly be right too, so take all the necessairy precautions. I've mainlined heroin before, was sure I was in a vein ( I used the same two veins for two years...please learn from that mistake), and experienced a burning, pins and needles sensation, followed by a nasty rash. I've once (and this sounds
real grimey, broken out in boils.) I am almost 100% certain this had to do with the cut, as I talked to other customers of the same connection who experienced similar reactions.
However, I also struck a nerve before and experienced similar results, though they were slightly different. It felt litterally like a ball of fire was running down my arms to the tips of my fingers. This was followed by a temporary lack of mobility in my hand (scared the
shit out of me as it was my drawing hand to boot) and some strange marks/patterns along the inside of my arm, as well as a lump on the back of my arm (which was confusing as it was no where near the injection site). After ten minutes I could use my hand again, though there was some lingering numbness, though that eventually faded too. I honestly thought I had hit an artery (as the burn shot down my arm,
away from my heart), but after talking to the nurses at my clinic, they led me to believe i had hit a nerve due to the lack of swelling. It was a real wake up call for me.
IMO, if the problem persists without any signs of going down after using antihistamine's, see a medical proffesional. It's humiliating, I know, but it beats the terror and paranoia of fearing you could lose your arm/hand.