Understanding Inherited Erythromelalgia: Diagnosis and Genetic Testing

Expert Reviewed By: ⁠Dr. Brandon Colby MD

Inherited Erythromelalgia (IEM) is a rare genetic disorder that affects the peripheral nervous system and causes episodic pain, redness, and swelling of the extremities. It is also known as Mitchell’s disease or primary erythromelalgia. While the condition can be challenging to manage, advancements in genetic testing have made it easier to diagnose and understand the underlying causes of IEM. In this article, we will explore the basics of inherited erythromelalgia, its diagnosis, and the role of genetic testing in managing this disorder.

What is Inherited Erythromelalgia?

IEM is a condition that primarily affects the blood vessels and nerves in the hands and feet. It is characterized by episodes of burning pain, redness, and swelling, which can be triggered by factors such as heat, exercise, or even wearing tight shoes. These episodes can last from minutes to hours and can significantly impact a person’s quality of life.

The condition is caused by mutations in the SCN9A gene, which is responsible for encoding a sodium channel protein called Nav1.7. This protein plays a crucial role in the transmission of pain signals in the peripheral nervous system. Mutations in the SCN9A gene lead to the overactivity of Nav1.7, which results in the symptoms of IEM.

Diagnosing Inherited Erythromelalgia

Diagnosing IEM can be challenging, as its symptoms can be similar to those of other conditions, such as Raynaud’s disease or cellulitis. A thorough clinical evaluation, including a detailed medical history and physical examination, is essential to rule out other possible causes of the symptoms. Additionally, a skin biopsy may be performed to examine the blood vessels and nerves in the affected areas.

Genetic Testing for Inherited Erythromelalgia

Genetic testing can play a vital role in diagnosing IEM, particularly when there is a family history of the condition. By analyzing a blood sample, genetic testing can identify mutations in the SCN9A gene that are associated with the disorder. This can help confirm the diagnosis and provide valuable information for managing the condition.

Benefits of Genetic Testing for IEM

There are several benefits to using genetic testing for the diagnosis and management of inherited erythromelalgia:

• Accurate diagnosis: Genetic testing can help confirm the diagnosis of IEM, particularly in cases where the symptoms are not typical or other conditions need to be ruled out.
• Family planning: For individuals with a family history of IEM, genetic testing can provide information about the risk of passing the condition on to their children. This can be helpful when making family planning decisions.
• Personalized treatment: Understanding the specific genetic mutation causing a person’s IEM can help guide treatment decisions and may lead to more effective management of the condition.
• Research and development: As more people with IEM undergo genetic testing, researchers can gain a better understanding of the disorder and work towards developing new treatments and therapies.

Managing Inherited Erythromelalgia

While there is currently no cure for IEM, there are several treatment options available to help manage the symptoms and improve the quality of life for those affected. These may include:

• Pain-relieving medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs), to help control inflammation and pain.
• Topical creams or patches containing local anesthetics, such as lidocaine, to numb the affected areas and provide temporary relief from pain.
• Anticonvulsant medications, such as gabapentin or pregabalin, which can help reduce nerve pain.
• Lifestyle modifications, such as avoiding triggers, wearing loose-fitting shoes, and using cooling measures to help manage symptoms.

In conclusion, inherited erythromelalgia is a rare and often misunderstood condition that can significantly impact a person’s quality of life. Genetic testing plays a crucial role in diagnosing the disorder and can provide valuable information for managing the condition. As research continues, it is hoped that new treatments and therapies will be developed to help those affected by IEM lead more comfortable and fulfilling lives.

About The Expert Reviewer

Dr. Brandon Colby MD is a US physician specializing in the personalized prevention of disease through the use of genomic technologies. He’s an expert in genetic testing, genetic analysis, and precision medicine. Dr. Colby is also the Founder of  and the author of ⁠⁠Outsmart Your Genes.

Dr. Colby holds an MD from the Mount Sinai School of Medicine, an MBA from Stanford University’s Graduate School of Business, and a degree in Genetics with Honors from the University of Michigan. He is an Affiliate Specialist of the American College of Medical Genetics and Genomics (⁠⁠ACMG), an Associate of the American College of Preventive Medicine (⁠⁠ACPM), and a member of the National Society of Genetic Counselors (⁠NSGC)