It’s not menopause (been checked for female & other hormonal issues), and tests for lupus are negative (I get the flushing on my face, among other places, and it can look a lot like a malar rash).
It can happen for no apparent reason or as a result of certain stimulation (some noxious, some benign). The duration of the flushing seems random...it can last for a couple minutes, to over an hour, to several hours; (I have had several episodes that last 2-6 hours). It occurs on one or more of the following body areas: palm(s), cheek(s), nose, ear(s), eyelid(s), and a patch of skin just above the elbow on the back of my arm(s) about 3"X3" in area. The skin gets very red, warm-to-hot to the touch, and literally feels like sunburn or scalding. It most often happens to my hands and cheeks.