Erythromelalgia
From Wikipedia, the free encyclopedia
| ICD-9 | 443.82 |
|---|---|
| DiseasesDB | 4476 |
| eMedicine | med/730 |
| MeSH | D004916 |
Erythromelalgia, also known as Mitchell's disease (after Silas Weir Mitchell) and red neuralgia, is a rare disorder in which blood vessels, usually in the extremities and especially in the feet, are blocked and inflamed, causing a painful burning and throbbing sensation and red skin. The attacks come and go, and tend to be worse in summer. Erythromelalgia is often associated with vascular diseases such as polycythaemia vera, thrombocytosis or with heavy metal poisoning.
Erythromelalgia responds to cooling, and sometimes disappears completely on taking non-steroidal anti-inflammatory drugs, such as aspirin. Cooling as a treatment is not recommended as the change in temperature may cause chronic cycles of flaring and dilation of the vessels in the extremities. There is no known permanent cure for erythromelalgia, and even with treatment, many patients still may feel the intense pain and discomfort and experience red, agitated skin at the onset of a flareup. secondary erythromelalgia is often accompanied by a malignancy. The pain associated with erythromelalgia is similar to shingles or complex regional pain syndrome and is very severe. Often sufferers cannot wear shoes, making it an extremely disabling condition.
A primary (or familial) form is termed erythermalgia. This occurs in patients who are younger. The disease is very rare. It has been linked to a mutation of the SCN9A (a sodium channel), the gene of which is located on the long arm of the second chromosome (2q24). It inherits in an autosomal dominant fashion.
The disease itself involves reduced skin capillary density during attacks ("flaring periods"). Is always worse in the later waking hours. Erythromelalgia is in fact itself a painful small fiber sensory/sympathetic mediated neuropathy(with rheumatological vascular dynamics). In the former respect would be similar to diabetic neuropathy, reflex sympathetic dystrophy and all other small fiber neuropathic pain syndromes.
Many sufferers of erythromelalgia find that spicy foods can also set off a flare-up. For others, a flare-up can be set off if pressure is applied to the extremities like fingers or toes. Erythromelalgia (in a mild form) can be detected by a stiff feeling, swelling, or redness in the limbs.
Raynaud's Disorder is the opposite of erythromelalgia and can occur simultaneously (but on different limbs).
Erythromelalgia is a complex enigma consisting of many neurovascular components. It is a channelopathy, and may serve as a model disease for many other diseases such as long QT syndrome, epilepsy and many others.
Recent genetic discoveries have indicated that the size of the linker in domain I S4-S5 of Nav1.7(sodium channel) seems to be influencing the gating properties(One uncharged amino acid is replaced for another).
Treatment for EM, involves trying different medications to see which suit the patient best. For example: anti-epileptics (lyrica), SSNRI's (Cymbalta or similar), certain calcium channel blockers (low dose with caution some can actually cause EM i.e. verapamil), tramadol, lidocaine patches, "off label" topical mixtures like (Ketamine and Elavil) combination gels in a plo base, aspirin(with caution). Some cases require stronger pain medications, spinal cord stimulators and pumps have been used with various success. Anti-oxidants and nutritional suppliments like vitamin C have also shown to help in trail studies for other similar diseases to EM(reflex sympathetic dystrophy and diabetic neuropathy). Natural alternative therapies have worked for some(Mg), RX should be tailored to fit the patient's needs and make them as comfortable as possible. Some may need sleeping or anxiety medications. Insommnia makes erythromelalgia worse.
[edit] External links
- http://www.erythromelalgia.org/ (Non profit organization)
- synd/934 at Who Named It
