It could be Shingles. It is usually a patch or area on the body that hurts to touch (doesn't itch though) and it is a form of herpes which usually comeout when your immunesystem is weak/fighting something (& you said you got a cold) or if you are super stressed and nervous... Shingles can also come out.
It could also be a reaction to something . allergy to something or Psoriosis
That's all that comes to mind. Feel better
Have you been checked for strep throat? Sometimes you can get a rash with strep throat.
rub the fleshy skin between your thumb and forefinger and press it also with feeling of pain ,drink plenty of water