Erythromelalgia is a rare condition that causes episodes of burning pain in the extremities. It mostly affects the feet, but people can also experience symptoms in the arms, hands, ears, legs, and face.
According to the National Organization for Rare Disorders (NORD), erythromelalgia (EM) is rare and can affect either one or both sides of the body.
In this article, we discuss the symptoms and causes of EM, as well as how to treat it and when to seek help.
EM is a rare disorder that can cause episodes of pain, swelling, and severely flushed skin, or erythema, in different parts of the body.
According to the NORD, other names for this condition include:
- Gerhardt disease
- Mitchell disease
- Weir-Mitchell disease
Healthcare professionals do not know the prevalence of this condition.
However, research suggests that it may affect 2 in 100,000 people, with new cases occurring at a rate of 1.3 per 100,000 people per year.
The NORD state that CM affects more females than males.
Some people may have had CM from early childhood, while it only affects others as adults. The authors of a 2018 review suggest that symptoms often begin before a person is 10 years of age, but it takes until they are over 40 to get a diagnosis.
The main symptoms of EM include:
- Erythema: This redness, which is often not apparent in darker skin tones, occurs due to excessive blood flow to the area.
- Heat: The extra blood flowing to the affected body part can cause the skin to be warm to the touch.
- Pain: The type of pain can vary, and a person may experience mild tingling, a pins-and-needles sensation, itchiness, or a strong burning feeling.
According to The Erythromelalgia Association (TEA), other symptoms can include:
- swelling of the affected area
- sweating more or less than the person usually would, but only in the affected area
- purple discoloration when they are not experiencing an episode
Although these symptoms are usually present in the feet, they can also occur in the hands, face, or other parts of the body.
The symptoms usually present bilaterally, meaning that they occur on both sides of the body. However, in some cases, they can occur on one side only.
According to the Genetic and Rare Diseases Information Center, triggers for EM episodes can include:
- increased body temperature
- eating spicy foods
Other triggers can include:
- wearing warm socks, gloves, or tight shoes
- entering a warm room
According to TEA, there are two main types of EM:
This type of EM does not occur due to an underlying condition or illness.
Healthcare professionals can classify primary EM as either inherited EM or idiopathic EM.
Inherited EM passes down genetically. It occurs due to a mutation in a gene called SCN9A, which affects how nerves send pain signals to the brain.
About 5–15% of EM cases occur due to this mutation.
The most common type of primary EM is idiopathic EM, in which there is no identifiable cause.
Secondary erythromelalgia occurs due to another illness or condition.
The most common causes include:
- nerve damage due to injuries or other conditions, such as carpal tunnel syndrome, sciatica, and frostbite
- autoimmune diseases, including lupus, vasculitis, and rheumatoid arthritis
- multiple sclerosis
- various blood disorders, including those that involve low platelet counts and blood cancers that cause increased production of platelets or red blood cells
Secondary EM can also occur due to certain medications, such as some antidepressants and calcium channel blockers. In these cases, the symptoms usually go away when a person stops taking the medication.
Erythromelalgia can be challenging to treat because no two cases are the same.
The response to different treatment options varies among individuals, and it can be a case of trial and error before a person, with the help of their doctor, finds what works for them.
If the EM is secondary to another illness or condition, the usual process would be to treat the primary condition first, in the hope that the EM will disappear.
However, in some cases, treating the primary condition has no effect on EM. These individuals will require treatment for the EM specifically.
The American Osteopathic College of Dermatology stress the importance of patience and open communication between a person with EM and their doctor to find an effective treatment.
Some of the treatment options include:
These can come in the form of creams, gels, sprays, or patches. They include lidocaine, a local anesthetic to help numb the pain, and capsaicin creams or patches, which make the heat receptors in the skin less sensitive.
A wide variety of different oral medications can help treat EM:
- Some antidepressants may help vascular control via the inhibition of serotonin reuptake.
- Aspirin may help by thinning the blood.
- Anticonvulsants may help reduce nerve activity.
A person with EM can take certain measures to manage their condition.
These include using air conditioning units or fans to keep the affected body parts cool and placing the affected body part in cool, but not cold, water.
According to the United Kingdom’s National Health Service, it is important to avoid using ice or anything too cold to relieve symptoms, as this can cause more damage to the area.
A person should also not soak body parts in cold water for extended periods.
EM is a rare condition that can cause flushed skin, pain, and swelling.
Flare-ups of the condition typically occur due to an increase in body temperature.
A person can try cooling techniques, such as using a fan or cold packs, to manage the symptoms.