What is the cause?

For most people witherythromelalgia,the cause is unknown.

However, in some cases, an underlying cause may be found usually a medical condition or a faulty gene (see below).

Underlying disease

Erythromelalgia sometimes results froman underlying disease, such as:

  • havingabnormally high levels ofblood cells either havingtoo manyplatelets in the blood (thrombocythemia) or too manyred blood cells ( Polycythaemia )
  • damage to the peripheral nervous system thenetwork of nerves outside the brain and spinal cord (this damage is known as peripheral neuropathy )
  • multiple sclerosis (MS) a disease of the nerves in the brain and spinal cord
  • anautoimmune problem such as lupus or rheumatoid arthritis , where the immune system attacks the body's own tissues

It may also result from certain medications, such as verapamil or nifedipine.

Genetic cause

In somepeople with erythromelalgia, the disease is caused by a change (mutation) in a gene. This may have occurred spontaneously or been inheritedfrom a parent, meaning that erythromelalgia can run in the family.

Genes contain the genetic information, or the "instructions", to make a particular protein in the body. Genetic mutations occur when DNA changes, altering the genetic instructions.

Erythromelalgia can be caused by changes in the SCN9A gene thatprovides the instructions for a sodium channel in pain nerves.

Changes in sodium channels can lead to them opening more easily and staying open longer than usual. This increases or amplifies pain signals.

It is not currently understood why the hands and feet are affected the most.

Content supplied by the NHS Website

Medically Reviewed by a doctor on 21 Dec 2018