I am not sure what it is, but I have red patches on both breasts, that have not gone away after many months and my PCP just gave me a prescription strength cream that isn't touching it. I agree, show the doctor, when I see my LLMD next month, I will show her red marks..
I am on one antibiotic by mouth that my my nurse friend told me to take, that my PCP only gave me because it helps skin infection ...NOT, but I was told to start with that medication as a good first step with the fight of Lyme until I move and see the LLMD. Let us know what happens.
I just did a quick search and discovered that red streaks may indicate infection and not necessarily a Lyme infection although I read a tick bite can have red streaks coming from it if there is an infection. Take a photo of it and see a doctor.
It could be a lot of things, but you already knew that, I'm guessing.
One thing it could be (since this is the Lyme forum) is an infection carried by the same tick that carries Lyme, called Bartonella, or 'cat scratch disease.' (Not that you got scratched by an actual cat, but that it looks like it.)
It could be other serious infections too, so I'd definitely see the doc. Let us know what you find out, okay? Best wishes --