During the past four weeks, I have had red hot blotchy somewhat itchy skin that comes and goes within 20 minutes...usually starts in my face/ throat / chest area - i feel it starting to flush and spreads quickly to arms, back and today to bottom half of body as well. First time I thought I was having a severe allergy and took allergy pill . But it disappeared on its own other times. I have no known allergies, am 43.... Incidents don t seem to have any connection?