Rare erythromelalgia causes burning in extremities
Q: Could you please address erythromelalgia? I'm told I have this condition, and from everything I've read, the prognosis isn't very uplifting. I've had mild symptoms for as long as five years, but now, at age 71, it's become much worse. Any information is greatly appreciated.
A: Erythromelalgia is a condition marked by periodic episodes of stinging or burning pain that occurs in the extremities, along with a rise in skin temperature and visible flushing in the affected area. It's a rare syndrome that affects fewer than 2 out of every 100,000 people. The condition is more common in women than in men, and although it can appear at any time of life, it's seen most often in middle age.
Erythromelalgia typically affects the feet. However, it can sometimes progress to involve the legs, arms or hands, and, very rarely, the ears or the face. The pain it causes is often intermittent and ranges from mild to severe. When mild, it's a distinct tingling sensation. Episodes of intense pain and heat can be severe enough that they interfere with standing, walking and sleep. Additional symptoms may include swelling of the affected body part and a purplish cast to the skin between flare-ups. The condition usually affects both sides of the body.
The specific underlying cause of erythromelalgia is not yet clear. Up to 15% of cases are attributed to a certain genetic mutation that interferes with the proper functioning of sodium channels. These are specialized proteins in the cell membrane that help with the transmission of electrical impulses.
Ongoing research suggests other cases may be tied to autoimmune disorders. Each of these is believed to interfere with the ability of blood vessels in the affected area to either widen or constrict in an appropriate fashion, thus leading to abnormalities in blood flow. Symptoms are often triggered by an increase in body temperature. This can happen following exercise, standing for a period of time, from a too-warm bath or shower, on a hot day, eating spicy food, stress or excitement, becoming dehydrated, or even wearing a warm pair of socks. Ambient temperatures in the low to mid-80s and above are associated with the onset of symptoms.
Although erythromelalgia cannot be cured, it can often be successfully managed. Once you're diagnosed, it's important to avoid the triggers we mentioned. Patients find that resting, avoiding stress, keeping the affected limbs elevated and exposing skin to cold air or cool water can relieve symptoms. It's important to avoid the use of ice or other more extreme means of cooling, as it's possible to damage the skin, and rewarming can cause a new flare. Your doctor may advise the use of certain cooling creams or gels, or something containing capsaicin, an active ingredient in chili peppers, which can desensitize heat receptors in the skin. Depending on the specific case, aspirin, anti-seizure meds or beta blockers may be prescribed.
The Erythromelalgia Association offers additional information, resources and support for this rare syndrome at erythromelalgia.org.
• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.