after SWIM iv'd his heroin into his hand.. which was definetly a hit his finger began to swell immediately and some of the rest of his hand began to rash.. he was worried for a while but the swelling has begun to subside and rash was completely gone within 20min.. he'd like to know why this happened hes been using the same vein in his hand for months and today the weird reaction I described above happened.. any thoughts or insight would be greatly appreciated by my friend thank you p.s new to the site sorry if I did this incorrectly