Introduction 

Erythromelalgia (erythro·mel·al·gia) is a rare condition where your hands and/or feet turn bright red, hot, and painful, especially when exposed to heat. These flare-ups can be spontaneous and are often triggered by heat or exercise.¹ While erythromelalgia is rare, its impact on daily life is profound. In this article, we will travel through the journey of erythromelalgia - from its historic beginnings and evolutionary genetic breakthroughs, to its modern-day implications and the ongoing search for effective management. 

History of erythromelalgia 

Early medical recognition and naming

The first detailed medical description of the condition we now know as erythromelalgia was observed by neurologist Silas Weir Mitchell in 1872, when he looked at four young adults experiencing burning pain and redness in their feet. Their symptoms worsened with heat or exercise and improved with rest and cooling - all patterns seen in erythromelalgia today. A few years later, in 1878, Dr Mitchell named the condition “erythromelalgia,” blending the Greek words: erythros (red), melos (limb), and algos (pain).²

Early theories 

In 1899, Mitchell and his colleague Spiller suggested that erythromelalgia might be caused by nerve problems - either in the limbs or deep within the spinal cord. At the time, the exact cause was unclear, but they believed it involved issues between blood vessels and nerves. 

Later on, reviews by Cassirer (1912) and May and Hillemand (1924) highlighted the difficulty in distinguishing erythromelalgia apart from other conditions like Raynaud’s syndrome and gout, among some others, as these illnesses share some similar symptoms, such as pain and redness, which made early diagnosis especially challenging.²

Terminology differences

In 1938, Smith and Allen switched out the term erythromelalgia for erythermalgia to highlight how heat (“therme”) is the main trigger in causing red, burning, and painful extremities. Interestingly, they found that for some patients, a single dose of aspirin (500 mg) could dramatically ease the burning pain for several days. Since then, both erythromelalgia and erythermalgia have been used to describe this condition, regardless of the form of erythromelalgia or whether the symptoms respond well to aspirin or not.²

The genetic breakthrough 

Primary erythromelalgia

The primary form of erythromelalgia is not linked to any other disease. It is a rare inherited condition that causes burning pain in your hands and/or feet in response to heat or exercise. In 2004, Yang discovered that primary erythromelalgia is caused by a change in a gene called SCN9A. This gene normally controls sodium channels in pain-sensing nerves within your body. However, when the gene is faulty, it makes these nerves overreact, leading to you feeling intense burning pain, especially in your hands and feet.^3,4

Secondary erythromelalgia

Secondary erythromelalgia, unlike primary erythromelalgia, has no gene involved and is linked to other diseases, such as blood disorders. In these cases, tiny blood vessels in your skin become inflamed or blocked due to overactive platelets (blood cells that help with clotting). This can trigger pain, redness, and swelling in your limbs. Your body’s inflammatory response can further activate clotting pathways, making symptoms worse.³

Modern understanding and patient experience

Symptoms

If you have erythromelalgia, you may experience a trio of symptoms, which most typically include burning pain, redness in your skin, and increased temperatures in your hands and/or feet. Although it mostly affects your hands/feet, some people may experience symptoms on their faces, ears, or genitals. Erythromelalgia can start at any age, including in childhood, but it is most often diagnosed in middle age. Pain tends to get worse with certain triggers, which include heat and exercise. Many people find relief by cooling their skin - this can be through using fans, cold water, or chilled socks and gloves. However, it is important to note that extreme cold exposure too often can cause other serious problems like skin damage, ulcers, frostbite, or even infections that may lead to sepsis or amputation.⁵

Impact on daily life 

Erythromelalgia does not follow a predictable pattern. Symptoms can come and go, but the pain is often intense and long-lasting. This can affect your ability to move, sleep, work, and connect with others - leading to a lower quality of life and, in some cases, serious health risks.⁵ 

Diagnosis

Currently, there is no single test to confirm erythromelalgia. Instead, doctors will usually make the diagnosis by looking at your symptoms. Since other conditions can look similar, genetic screening may be needed to rule out other diseases such as peripheral neuropathy.⁵

Treatment

Thankfully, there are multiple ways in which you can help treat and manage your symptoms. 

For both primary and secondary erythromelalgia, trying your best to avoid trigger factors is a good place to start. In other words, you should try to avoid heat exposure. A few ways this can be done are by limiting physical activities or staying in colder environments. You may also wish to submerge your hands/feet in cold water or apply ice to them, but in doing so, you should ensure that your level of cold exposure is balanced so as not to cause any harm to your skin or overall health. There are also other options, such as topical agents like capsaicin cream, which is good for treating the localised symptoms of erythromelalgia.

Since scientists discovered that a faulty gene (SCN9A) causes primary erythromelalgia, new treatments, such as the drug mexiletine, have focused on calming the overactive sodium channels (called Nav1.7) in pain-sensing nerves.

Secondary erythromelalgia, on the other hand, is to be treated slightly differently. Since this type is linked to another underlying disease, treatment options involve treating that disease, which can be helpful in controlling symptoms.

Managing erythromelalgia requires a team-based approach, where doctors can look at how the pain affects your daily life, such as when walking, sleeping, and going to school or work.^4,5 Treatment is not just about reducing pain - it’s also about helping you function better in your daily life.

Ongoing challenges and future directions 

Research gaps 

There is a lack of epidemiological data on the incidence of erythromelalgia. One study from Minnesota, USA, estimated that about one in 100,000 people are diagnosed with the condition each year. It also found that women are slightly more likely to be affected than men. The study looked at medical records between 1976 to 2005 and separated cases into primary and secondary forms. However, since then, our understanding of primary erythromelalgia has changed, especially with the discovery of genetic mutations, so the older definitions may now be outdated. The incidence figures we do have could even be underestimated, as oftentimes, erythromelalgia goes unrecognised.⁴

Future research

To better understand and treat erythromelalgia, future studies need to be larger, involve multiple research centres, and follow patients over longer periods of time. This helps doctors learn which treatments are safe and effective in the long run. Researchers should also look at genetic differences, especially changes in the SCN9A gene, to help tailor treatments to each person, known as personalized therapy. Finally, studies should use consistent ways to measure results, so that findings from different research teams can be compared and combined. This makes it easier to build strong, reliable evidence that can improve care for everyone living with erythromelalgia.⁶

Summary

Erythromelalgia’s evolution from a historically misunderstood burning pain to a genetically defined disorder reflects years of scientific perseverance and patient resilience. Despite the lack of epidemiological data, research on erythromelalgia is still ongoing and advances are being made, including but not limited to the genetic discovery of mutations in the SCN9A gene. This growth in research can empower patients, validating their experiences and connecting them to a growing community. Understanding the history of erythromelalgia offers hope and clarity, especially for those who have struggled to find answers - but the journey is far from over. Greater awareness, improved diagnostic tools, and compassionate care are urgently needed. Future research must be reliable, genetically informed, and focused on long-term outcomes. With better support from a team of healthcare professionals, we can advance toward more effective treatment and improved diagnosis for individuals living with erythromelalgia through better research and clinical care.