Erythromelalgia in hands of a 52-year-old Swedish man with small fiber neuropathy (sensory and autonomic), also suffering from erythromelalgia in feet and ears. Erythromelalgia is a rare, neurovascular disorder in which blood vessels, usually in the lower extremities and/or hands, are episodically blocked (frequently on and off daily), then become hyperemic and inflamed. There is severe burning pain (in the small fiber sensory nerves) and skin redness. Most patients suffering from erythromelalgia experience flares when exposed to heat, even at very moderate temperatures, for example, when washing one's hands in lukewarm water. Friction or pressure can have the same effect. In this picture, the patient had been holding a book for ten minutes, enough to cause this flare-up.