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Erythromelalgia (EM) is an extremely rare condition affecting the feet and sometimes the hands. It is known for causing intense burning pain, severe redness, and increased skin temperature that is either episodic or continuous.
The word erythromelalgia comes from three Greek words: "erythros," which means redness, "melos," meaning limb, and "algia," meaning pain. The condition was formerly known as Mitchell’s disease after American physician and writer, Silas Weir Mitchell.
One study finds that EM affects an estimated 1.3 people out of 100,000 per year in the United States—it affects more women than it does men.1
Symptoms
Traditionally, EM has been classified as either primary or secondary. However, the use of these terms is debated because of the uncertainty regarding the relationship between erythromelalgia and comorbidities.
In general, the most common symptoms of EM are swelling, tenderness, a deep painful aching of soft tissue (radiating or shooting sensation), and painful burning sensations in the hands and feet. The feet are more often affected, but symptoms can also affect the hands, face, and eyes.
Primary EM
Primary EM relates to certain genes or is idiopathic, meaning it has no known cause. This type of EM is more common in children—especially in the first decade of life—but anyone of any age can be affected. For some young people, symptoms may start during puberty.
In primary EM, burning pain, redness, and warmth are the most common symptoms, and these can be debilitating. The pain usually affects both sides of the body—both hands, for instance—is sporadic and severe, and will often affect the feet more than the hands.
Primary EM pain attacks start with itchiness and will progress to severe burning pain. These pain attacks can last for minutes, hours, or even days.
Attacks tend to be worse with warmer weather and at night and can be triggered by heat, sweating, exercise, or sitting or standing for too long. In some cases, the feet can develop ulcers (sores) and gangrenes (dead tissue).
Secondary EM
Secondary EM is associated with other diseases or conditions, especially autoimmune diseases and myeloproliferative disorders (diseases of the blood and bone marrow). It is more common in adults, with onset generally occurring in middle age.
The symptoms of secondary EM occur when a person is exhibiting symptoms of the underlying condition. Symptoms of secondary EM will present gradually and will worsen in a short time. Burning pain, redness, and warmth are also experienced by people with secondary EM.
Causes
There are specific risk factors and causes associated with both primary and secondary EM. These may include age, genetics, autoimmune diseases, and a host of other conditions.
Age and Genetics
Primary EM is more common in children and teenagers, while secondary EM is more common in adults. SCN9A is the genetic mutation affecting up to 15% of people with EM. Genetic mutations are inherited, but they can also be new mutations.
Associated Diseases
People with autoimmune diseases, such as diabetes or lupus, are believed to have a higher risk for EM. EM is also suspected to occur due to the presence and triggering of other health conditions including myeloproliferative diseases. Some neurological diseases increase risk, including multiple sclerosis.
Other Health Factors
Heavy metal poisoning has been linked to EM. This is likely the result of when toxic amounts of these substances, such as mercury and arsenic, enter soft tissues in the body. Heavy metal poisoning can be caused by industrial exposure, air or water pollution, and exposure to foods, medicines, and lead-based paints.
Some medications including ergot derivatives have been linked to EM. (Ergot derivatives treat severe headaches, including migraines.)
Diet has also been linked to EM. Spicy foods and over-consumption of alcohol, for example, are commonly reported triggers for EM flares.
Nerve damage from other conditions, including sciatica and frostbite are risk factors, as well as peripheral neuropathy, including diabetic neuropathy. Neuropathy is the result of damage to peripheral nerves—nerves located outside of the brain and spinal cord—that carry information to muscles. Neuropathy causes weakness, numbness, and pain in the hands and feet.
Aside from genetics, many causes and risk factors are speculative and researchers believe that in the majority of people, the cause of EM is unknown.
Diagnosis
There is no specific testing for EM. This condition is diagnosed by observing symptoms and ruling out other possible causes. Tests may be done to rule out other conditions, including bloodwork and imaging. Children with symptoms of primary EM and a family history of the disease may also be tested for genetic evidence of the SCN9A mutation.
Treatment
There is no single treatment for EM, and there is also no cure. In secondary EM, treating the underlying condition may bring about relief. Most of the time, however, EM cannot be fully treated. In these situations, doctors will focus treatment on symptom relief.
Treatment options should follow a stepwise approach that begins with non-pharmacological measure, followed by topical medicines, oral medications, pain rehabilitation programs and in extreme cases, surgery. It may take some time to find a treatment plan that works.
Cooling the affected areas with cold packs and elevating flaring feet can help with coping.
Surgery is considered when no other treatments provide relief. The surgical procedure, called a sympathectomy, cuts nerve endings that transmit pain signals to the hands and feet. There are serious risks associated with this surgery, including bleeding, infection, and nerve damage. Doctors will only consider sympathectomy when a person’s quality of life is significantly affected by EM.
A Word From Verywell
Though there is no cure for erythromelalgia, the outlook can still be positive. Treatment may bring about complete relief of symptoms—most of the time, however, EM cannot be fully treated. Treatment takes some trial and error to find a plan that works to relieve symptoms. As advances in treatment and research are occurring, there is more hope for having a positive quality of life with EM.