This is a rare condition that presents redness, intense burning pain, increased skin temperature that commonly affects the feet and the hands. It can also involve other parts of the body such as the arms, hands, faces, ears and the nose. This condition can affect the individual’s normal daily functions such as standing, walking, working or sleeping and hence various alterations to their lifestyles may be necessary to prevent the flare-ups. It is estimated that around five percent of these cases are inherited as the result of genetic mutations. Research indicates that around 1.3 per 100,000 individuals appear to be diagnosed with this condition per year in the United States.
Causes
It is estimated that around 15% of the cases are the result of the mutation in the gene SCN9A that can cause erythromelalgia. This gene is responsible for providing the instructions to produce the NaV1.7 sodium channels essential for the cells ability to make and deliver electrical signals. This channel is found in the nerve cells which transmit pain signal to the brain and the spinal cord. The problem with the sodium ions enhances the transmission of pain signals resulting in the symptoms that are associated with this condition. In some cases, it can develop as the result of an underlying disease such as abnormally high levels of blood cells, an autoimmune problem or multiple sclerosis.
Symptoms
This condition presents severe, burning pain that involves redness of the skin and an increase in the skin temperature. The hands appear to be the primary sites of the problem which can either involve both the sides of the body (bilateral) or the single side of the body (unilateral) particularly when it develops as the secondary condition resulting from an underlying disorder (secondary erythromelalgia). The onset may be gradual over several years or can begin suddenly. In some cases, this can spread rapidly, deteriorating and possibly disabling the individual over weeks. In the severe cases, the condition can spread from feet up the legs, hands up the arms or to the ears and the face. The symptoms can also be triggered by an increase in body temperature such as dehydration, wearing tight gloves or with an increase in the room temperature.
Diagnosis
The diagnosis is based on the evaluation of the individual’s history, family history and in the identification of the characteristic symptoms of the disease. As other underlying conditions can also occur in association with erythromelalgia, various tests are necessary to confirm or rule out other diseases. This can include regular blood cell counts and other specialized tests to ensure that the individual is effectively treated for the underlying disorders. In order to make the proper diagnosis, a flare may be provoked by immersing the affected region in hot water for a period of time.
Treatment
Cooling the skin can relieve the symptoms and raising the affected limb may help relieve the pain. A combination of treatment may be required for different individuals as a single medication treatment does not prove to be effective for all the affected cases. Various medications can help in relieving the pain that may be caused by the damage to the nervous system. Other medications can include those used for high blood pressure to widen the blood vessels and aspirin for adults if high number of blood cells appears to be the cause of the symptoms. In some cases, an intravenous infusion may be used when oral medication is ineffective.
References
https://ghr.nlm.nih.gov/condition/erythromelalgia#inheritance
https://rarediseases.org/rare-diseases/erythromelalgia/
http://www.nhs.uk/conditions/erythromelalgia/Pages/Introduction.aspx
http://www.dermnetnz.org/topics/erythromelalgia/
http://www.erythromelalgia.org/whatisem.aspx
