Erythromelalgia By Koon K Teo, MBBCh, PhD, McMaster University Reviewed / Revised May 2021 | Modified Sep 2022 View Patient Education Erythromelalgia is distressing paroxysmal vasodilation of small arteries in the feet and hands and, less commonly, in the face, ears, or knees; it causes burning pain, increased skin temperature, and redness.