A. While many once believed caffeine was a common rosacea trigger, a study found that it is instead the high temperature of heated beverages that causes immediate facial flushing.1 The study found that at room temperature (72 degrees) neither caffeine nor coffee led to flushing reactions. However, drinking either hot coffee or hot water, each heated to 140 degrees, caused facial flushing of similar types and intensity.
It may be possible that in some cases caffeine might contribute to emotional stress, which has been reported to be a leading rosacea tripwire for many patients.
A.There is no generalized answer to your question, since the location and manifestations of rosacea can vary substantially from one patient to another. It is possible that rosacea affects a particular part of your face because of previous physical trauma in that area, localized exposure to an aggravating factor or simply the individual physical characteristics of your face.
What is most important, of course, is to try to prevent flare-ups in the first place. Beyond medical help, if you can identify and avoid your personal rosacea triggers, you may be able to reduce the frequency of your flare-ups.
Wilkin J. Oral thermal-induced flushing in erythematelangiectatic rosacea. Journal of Investigative Dermatology. 1981;76(1):15-18.