Erythromelalgia is a rare condition that causes burning pain, redness and hot skin, mostly in the feet. The pain can be constant or it may come and go. It can be hard to treat, but avoiding triggers can help.

Cooling the affected area may relieve symptoms. Avoid frequent immersion in cold water as this can cause a vicious cycle.

Symptoms

Erythromelalgia is characterized by episodes of pain, redness and warmth of the extremities, most often in the feet and hands. In most people with EM, these episodes are episodic and come and go (asymmetrical). The pain may be severe enough to interfere with daily activities. It may be on-going (chronic) in some people and sometimes leads to skin ulcers or even tissue death (necrosis).

The onset of EM is usually gradual, with flare-ups occurring over weeks or months. In some people, the condition can be triggered by increased body temperature such as from exercise or warm weather, or by wearing tight shoes and socks. Drinking alcohol, eating spicy foods or feeling stressed may also trigger an episode of EM.

In a few cases, erythromelalgia is caused by an underlying disease such as autoimmune diseases, polycythemia vera, or damage to nerves. In these cases, identifying and treating the underlying disease can help relieve erythromelalgia symptoms. Treatment of EM often includes medications you take by mouth, such as drugs that reduce blood pressure or increase pain relief, and creams you apply to your skin.

Diagnosis

The disorder is characterized by episodes of red (erythro-) skin and severe burning pain in the feet and, less commonly, in the hands (extremities). These symptoms are triggered by increased body temperature, such as when stepping out into a warm or hot environment. They may also be triggered by exercise or wearing tight shoes or clothing. The symptoms occur on both sides of the body (bilateral) but sometimes affect only one side (unilateral). EM can be on-going (chronic) or come and go (episodic).

In most cases of EM, there is no identifiable cause. However, it can be associated with myeloproliferative disorders (where the bone marrow produces excess blood cells), paraneoplastic diseases and occasionally with rheumatic or infectious diseases. EM has also been linked to mutations of the sodium channel (SCN9A), which encodes for the Nav1.7 type of nerve cell receptor. These mutations lead to dysregulation and hyperexcitability of the neurons that detect nerve-related pain. This leads to the dilation of the small blood vessels that are responsible for the symptoms in EM.

Treatment

The condition can cause flare-ups of burning pain and red skin that sometimes affect your arms, legs and face. The pain can be constant or it can come and go, with a period of symptom-free days in between. Taking medication, staying cool, and avoiding triggers can help.

If it’s not clear what causes your erythromelalgia, your doctor may refer you to a specialist. They will ask about your symptoms and do tests. These can include blood tests to look for changes in your genes (genetic testing) or other health conditions that may be causing your symptoms.

Most people with erythromelalgia live long lives, though they often have to cope with painful episodes. If the pain is affecting your quality of life, counselling or cognitive behavioural therapy may help. Support is available from organisations such as Genetic Alliance Australia and Healthdirect Australia. You can also contact the nurse-on-call service 1800 022 222. You can call this number for free and speak to a registered nurse 24 hours a day, 7 days a week.

Prevention

There is no cure for EM, but a person may improve their quality of life by following some simple steps. Avoiding exercise, strenuous activity and excessive warming of the feet or hands (by using fans, cold water, cooling socks and gloves) is important during outbreaks. Topical menthol creams, gels and sprays can help reduce pain during episodes. Some patients find relief by taking oral medications that can reduce the number of occurrences of EM, such as amitriptyline, lidocaine and capsaicin. For those whose EM is a result of an underlying condition, such as essential thrombocytosis or myelodysplastic syndrome, treatment for the underlying cause can help alleviate symptoms.