I am an IV drug user , I ve never had an abscess before so I don t really know if that s what s happening or not . I ve missed my vein before and this hasn t happened , but I do shoot very close to an artery so I m also wondering If I could have shot into my artery . I mixed a shot of heroin and cocaine . I shot on the left side of my neck and I started noticing a really small purplish lump/bump coming up where I shot up at , and there was a splotchy red rash that started coming up around my ears and all over my neck and chest area and over to my right side behind my ear too . It s not a bad rash . You can definitely see it but it s not terrible Can you tell me what this is and how I can start quickly treating it ?