My hot flashes triggered massive rosacea flushing too.
Here are the options I saw:
1. Do nothing. This was untenable for me, as the flushing was so bad that I could not sleep or eat. It also causes cumulative damage and is to be avoided if possible.
2. Take Estrogen. This worked great for me until it gave me a blood clot. The problem with this method, too, is that some day, you WILL have to get off the estrogen, and when you do, the rosacea will come roaring back.
3. Other meds. I found Remeron (mirtazapine), which shuts down nearly all the hot flashes and thus the flushes, and Clonidine, which does the same. Drawbacks are the Remeron makes me sleepy and hungry. For me, the benefit outweigh the drawbacks of this option.
Hope this helps.