Erythromelalgia is also called Mitchell's disease or erythermalgia.

Causes of erythromelalgia

There are two types of erythromelalgia – primary and secondary.

Primary erythromelalgia doesn’t have a known cause. It can run in families, but this is quite rare.

Secondary erythromelalgia has a known cause. It can be caused by too many platelets, which are blood cells that help blood to clot when bleeding. Other causes include:

• diabetes
• lupus
• some diseases of the brain and nervous system
• polycythaemia vera (too many red blood cells)

Symptoms of erythromelalgia

Flare-ups often begin with a mild itch. The itch gradually changes to burning pain. The painful area becomes red, swollen and sometimes sore to touch.

Erythromelalgia usually affects the hands or feet on both sides of the body. However you can get it in other areas, or just on one side.

The pain can come and go, and is more common in the evening and night. The pain is relieved by cooling the area or elevating it.

Erythromelalgia can be mild, but it can also be very severe. It can be worse in warm weather, or when your hands and feet get hot (for example, wearing socks and shoes). Severe erythromelalgia can cause ongoing pain and affect your quality of life. It can also interfere with walking and other activities.

Diagnosis of erythromelalgia

To diagnose erythromelalgia, your doctor will need to know how it looks and feels during an attack. It can help to take photos of your skin during a flare-up, to show your doctor.

Your doctor might also ask you to put your feet or hands in warm water so they can see what happens.

If you have erythromelalgia, you might be asked to have a blood test. This is to see if your erythromelalgia is caused by too many platelets or blood cells.

Treatment of erythromelalgia

Erythromelalgia can't be cured, but primary erythromelalgia sometimes gets better by itself.

Many people find gently cooling the area helps. Raising the affected area can also help.

If you have erythromelalgia, wearing loose clothing and not letting yourself get too hot can help prevent or reduce attacks.

Keeping the room at a steady temperature can be helpful. Avoiding strenuous exercise or wearing too much clothing can also help.

Other treatments that have helped some people include:

• aspirin
• capsaicin cream
• anticonvulsant medicines (such as gabapentin)
• antidepressants (for example, tricyclics)
• calcium channel blocker medication
• anaesthetic medication through a drip
• surgery to stop the nerve pain

Using cold water for long periods (such as in an ice bath) is not recommended as it can cause tissue damage and ulcers.

What works for one person may not work for another. Treatments can also have risks and side effects. Talk to your doctor about what treatment might be best for you.