Erythromelalgia: A disorder characterized by
vasodilatation associated with paroxysmal, intense burning pain, and
episodic reddening of the extremities (mainly feet). The symptoms of
redness, heat, pain, and swelling, when not associated with organic disease,
constitute the primary form, which has also been termed “erythermalgia”
because of the significance of the heat. The secondary or acquired form is
related to underlying medical conditions.