This rare disorder may be
Primary (cause unknown)
It may also be secondary to
Myeloproliferative disorders Overview of Myeloproliferative Neoplasms Myeloproliferative neoplasms are clonal proliferations of bone marrow stem cells, which can manifest as an increased number of platelets, red blood cells (RBCs), or white blood cells (WBCs)... read more (eg, polycythemia vera Polycythemia Vera Polycythemia vera is a chronic myeloproliferative neoplasm characterized by an increase in morphologically normal red cells (its hallmark), but also white cells and platelets. Ten to 15% of... read more , thrombocythemia Essential Thrombocythemia Essential thrombocythemia (ET) is a myeloproliferative neoplasm characterized by an increased platelet count, megakaryocytic hyperplasia, and a hemorrhagic or microvascular vasospastic tendency... read more )
Spinal cord disorders
Less commonly, the disorder is related to the use of some drugs (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 Raynaud Syndrome Raynaud syndrome is vasospasm of parts of the hand in response to cold or emotional stress, causing reversible discomfort and color changes (pallor, cyanosis, erythema, or a combination) in... read more 
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 Peripheral Neuropathy Peripheral neuropathy is dysfunction of one or more peripheral nerves (the part of a nerve distal to the root and plexus). It includes numerous syndromes characterized by varying degrees of... read more , causalgia, Fabry disease Fabry Disease Fabry disease is a sphingolipidosis, an inherited disorder of metabolism, caused by deficiency of alpha-galactosidase A, which causes angiokeratomas, acroparesthesias, corneal opacities, recurrent... read more 
, and bacterial cellulitis Cellulitis Cellulitis is acute bacterial infection of the skin and subcutaneous tissue most often caused by streptococci or staphylococci. Symptoms and signs are pain, warmth, rapidly spreading erythema... read more 
.
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.
