One other possibility if you have burning there is that it is the first stages of
shingles, which would be a lot less worse than
HIV. As far as I know, shingles outbreak could be triggered by any other virus, or just by stress.
Can I ask you- what was your source for labelling a sunburn type rash (I have it in the same place, but just on one side of neck) as ARS? Wikipedia says that it's a maculoupoular rash, that it DOES have raised bumps similar to what you would get with measles.