What is it?
Erythromelalgia, also known as EM is a rare disorder that typically affects the skin of the feet or hands, or both, and causes intermittent, painful swelling, visible redness, intense heat and burning pain. Sometimes the legs and arms can be affected or less often, other areas such as the ears or nose. It usually affects both sides of the body, but can affect just one. In ancient Greek, ‘Eythros’ means ‘red’ and ‘melalgia’ means pain in a limb. Early onset erythromelalgia starts before the age of 25, and late onset develops between the ages of 40 to 60.
Persons with the disorder often make major adjustments to their lifestyles to avoid flares. Even in mild to moderate cases, normal functioning such as walking, standing, working, socialising, exercising, and sleeping may be impaired. The associated pain and burning sensations can be extremely severe.
Approximately five percent of those with the disorder have an inherited condition that research has shown to be caused by genetic mutations. These people usually have other members of their families with the syndrome.
The cause is unknown in the vast majority of cases. Peripheral neuropathies underlie many, and in some cases EM may be secondary to other disorders like the blood disease polycythemia. While the specific underlying cause of the ailment remains unknown, the condition is also thought to result from vasomotor abnormalities or dysfunction in the normal narrowing and widening of the diameter of certain blood vessels, leading to abnormalities of blood flow to the extremities.
Erythromelalgia may be an isolated, primary condition, or occur secondary to various underlying disorders. Primary erythromelalgia may appear to occur randomly for unknown reasons (sporadically) or may be familial. The secondary form can be associated with other diseases including diabetes mellitus, rheumatoid arthritis, gout, human immunodeficiency virus and systemic lupus erythematosus.
Is it hereditary?
Primary erythromelalgia can run in families and may be traced to a particular gene. However there is usually no family history.