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.
This rare disorder may be
Primary (cause unknown)
It may also be secondary to
Myeloproliferative disorders (eg, polycythemia vera, thrombocythemia)
Spinal cord disorders
Less commonly, the disorder is related to the use of some medications (eg, nifedipine, bromocriptine).
A rare hereditary form of erythromelalgia starts at birth or during childhood.
Symptoms include burning pain, heat, and redness in the feet or hands that lasts a few minutes to several hours. In most patients, symptoms are triggered by warmth (temperatures of 29 to 32° C) and are typically relieved by immersion in ice water. Trophic changes do not occur. Symptoms may remain mild for years or become severe enough to cause total disability. Generalized vasomotor dysfunction is common, and Raynaud syndrome may occur.
Diagnosis of erythromelalgia is clinical. Testing is done to detect causes. Because erythromelalgia may precede a myeloproliferative disorder by several years, repeated blood counts may be indicated.
Differential diagnosis includes posttraumatic reflex dystrophies, shoulder-hand syndrome, peripheral neuropathy, causalgia, Fabry disease, and bacterial cellulitis.
Treatment of erythromelalgia is warmth avoidance, rest, elevation of the extremity, and application of cold. For primary erythromelalgia, gabapentin may be of benefit. For secondary erythromelalgia, the underlying disorder is treated; aspirin may be helpful when a myeloproliferative disorder is the cause.