Erythromelalgia:

Erythromelalgia: 

Erythromelalgia is a rare disorder characterized by burning pain, warmth, and redness, predominantly involving the extremities.  The feet are more frequently involved than the hands. Rarely, non-extremity involvement is seen in areas such as the face and genitals.

A distinction is generally made between primary (idiopathic or genetic) and secondary erythromelalgia (most commonly associated with myeloproliferative disorders), as well as between early- and late-onset disease.

Causes

There are a few types and subtypes of erythromelalgia, each with its own causes. These types include: 

Primary erythromelalgia 

Primary erythromelalgia occurs in isolation without any underlying diseases. There are two primary types: 

Idiopathic: The most common form of erythromelalgia. It occurs with no known cause.

Inherited: A defective gene is passed down from parent to child.

Secondary erythromelalgia 

Secondary erythromelalgia results from an underlying condition relating to neurological, blood, or immunological disorders. These conditions include: 

• Lupus, multiple sclerosis, and other autoimmune disorders 
• Essential thrombocythemia – a disorder of the blood that makes your body develop too many platelets 
• Polycythemia vera – a type of blood cancer 
• Raynaud’s phenomenon – a condition that affects certain body parts, making them feel numb and turn different colors 
• Thrombocytopenia – a condition in which the platelet count in your blood is lower than it should be
• Neuropathy – damaged or defective nerves resulting in muscle weakness, numbness, tingling, and pain in affected areas

Symptoms 

The pain from erythromelalgia can come and go. These are known as flares or episodes. Flares are more common in the evening and night.

Flares often involve painful, burning areas of skin that are also: 

• itchy
• red
• swollen
• warm
• tender and 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.
• Erythromelalgia can be mild, but it can also be very severe.

Flares can be made worse in warm conditions, caused by:

• warm weather
• a hot bath or shower
• wearing socks and shoes
• physical activity
• stress

Diagnosis 

There’s no specific test for diagnosing erythromelalgia. Your healthcare provider reviews your symptoms and examines any active flare-ups or photos of flare-ups. Multiple tests may be necessary to confirm your symptoms and rule out other medical issues. These include:

• Blood tests.
• Genetic testing to check for mutations responsible for the disease.
• Thermography, which uses a special camera to pinpoint differences in skin temperature.
• X-ray or other imaging studies.

Note: For purposes of this section, a characteristic attack of erythromelalgia consists of burning pain in the hands, feet, or both, usually bilateral and symmetrical, with increased skin temperature and redness, occurring at warm ambient temperatures. These evaluations are for the disease as a whole, regardless of the number of extremities involved.