Erythromelalgia: An Underrecognized Manifestation of Small-Fiber Neuropathy

Symptoms and Treatments Recommend a Doctor, Therapist, or Clinic (Positive
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A must read for EM patients from the Mayo Clinic.

A recent study showed that a predominantly small-fiber neuropathy underlies most cases of erythromelalgia. Link below.

http://www.mayoclinicproceedings.org/article/S0025-6196(11)61198-1/fulltext


Full text/

Erythromelalgia is characterized by intermittent heat, redness, and pain affecting the extremities.1x1Smith, LA and Allen, EV. Erythermalgia (erythromelalgia) of extremities: a syndrome characterized by redness, heat, and pain. Am Heart J. 1938; 16: 175–188
See all References1 Exercise and increase in temperature are precipitating factors. During symptoms, blood flow and temperature increase without a concomitant increase in oxygenation.2x2Sandroni, P, Davis, MDP, Harper, CM et al. Neurophysiologic and vascular studies in erythromelalgia: a retrospective analysis. J Clin Neuromuscul Dis. 1999; 1: 57–63
CrossRef | PubMedSee all References2 Severe sudomotor impairment and evidence of peripheral adrenergic dysfunction are also present.2x2Sandroni, P, Davis, MDP, Harper, CM et al. Neurophysiologic and vascular studies in erythromelalgia: a retrospective analysis. J Clin Neuromuscul Dis. 1999; 1: 57–63
CrossRef | PubMedSee all References2 A recent study showed that a predominantly small-fiber neuropathy underlies most cases of erythromelalgia.3x3Davis, MD, Sandroni, P, Rooke, TW, and Low, PA. Erythromelalgia: vasculopathy, neuropathy, or both? a prospective study of vascular and neurophysiologic studies in erythromelalgia. Arch Dermatol. 2003; 139: 1337–1343
CrossRef | PubMed | Scopus (62)See all References3 The presence of intermittently increased blood flow and shunting suggests an associated vasculopathy.4x4Davis, MD, Rooke, TW, and Sandroni, P. Mechanisms other than shunting are likely contributing to the pathophysiology of erythromelalgia [letter]. J Invest Dermatol. 2000; 115: 1166–1167
CrossRef | PubMed | Scopus (13)See all References4 Erythromelalgia has been reported in association with myeloproliferative disorders, but the cause-effect relationship is not well established.5x5Babb, RR, Alarcon-Segovia, D, and Fairbairn, JF II. Erythermalgia: review of 51 cases. Circulation. 1964; 29: 136–141
CrossRef | PubMedSee all References5

A 43-year-old woman was evaluated because of a 6-month history of intermittent tingling in her feet accompanied by redness, warmth, and pain. Exposure to heat and exercise often precipitated her symptoms. Results of neurological examination, nerve conduction studies, and electromyography were unremarkable. Evaluation of the autonomic nervous system (heart rate response to deep breathing, tilt-table test, Valsalva maneuver, quantitative sudomotor axon reflex test) yielded normal findings. A thermoregulatory sweat test showed evidence of anhidrosis or hypohidrosis in patchy areas (shown in yellow) over the lateral aspects of the arms, fingers, and lower limbs (including distal aspects of the feet) in a pattern consistent with multifocal small-fiber neuropathy. Arterial Doppler studies showed no evidence of occlusive disease. Provocative vascular studies in the lower limbs revealed evidence of increased blood flow and temperature without an increase in oxygenation.

Erythromelalgia as a manifestation of small-fiber neuropathy is not well recognized. Neuropathy and vasculopathy often coexist, and erythromelalgia may represent a predominant small-fiber neuropathy with disturbed control of vascular tone.3x3Davis, MD, Sandroni, P, Rooke, TW, and Low, PA. Erythromelalgia: vasculopathy, neuropathy, or both? a prospective study of vascular and neurophysiologic studies in erythromelalgia. Arch Dermatol. 2003; 139: 1337–1343
CrossRef | PubMed | Scopus (62)See all References3 Awareness of this entity will help ensure appropriate work-up and management of patients with small-fiber neuropathy. Erythromelalgia is the first inherited pain disorder in which a mutation has been linked with an abnormality in ion channel function. A mutation has been identified in the SCN9A gene.6x6Yang, Y, Wang, Y, Li, S et al. Mutations in SCN9A, encoding a sodium channel alpha subunit, in patients with primary erythermalgia. J Med Genet. 2004; 41: 171–174
CrossRef | PubMedSee all References6 This gene encodes the voltage-gated sodium channel α subunit Nav1.7. Nav1.7 is expressed by nociceptive neurons, and recent evidence suggests that Nav1.7 plays a role in transmission of nociceptive information.7x7Cummins, TR, Dib-Hajj, SD, and Waxman, SG. Electrophysiological properties of mutant Nav1.7 sodium channels in a painful inherited neuropathy. J Neurosci. 2004; 24: 8232–8236
CrossRef | PubMed | Scopus (166)See all References7 Identification of erythromelalgia as a channelopathy suggests the possibility of rational therapies targeting the affected channel.

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Thank you so much for posting this. I find it very interesting and something that makes sense to me because of the symptoms I have and the way I feel. First time for me to say - that sounds right. If small fiber neuropathy is the underlying issue what kind of a doctor would be best to consult? A Neurologist?

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Thank you so much fixme for raising awareness on this .Its so very kind of you to care and share with your fellow EM-ers ((((fixme))))))))

EM is small nerve fiber neuropathy by any other name.

We have several old posts on SNF if members would like to scroll back through the topics and have a read.

I have re- uploaded a couple I thought of particular interest.

Wishing all my EM family a 'comfortable' day

God bless

234-AutonomicandSmallFiberNeuropathyStanfordHospitalClinics.htm (27.8 KB) 235-ErythromelalgiaIsaSmallFiberNeuropathy.htm (36.3 KB)
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Hello All,

If EM is supposed to be Small Fiber Neuropathy, and I was tested by skin biopsies ( more than one) for SFN and the biopsies were NEGATIVE for SFN- then do you think I don't really have Em or can you have EM but have normal tests for SFN?

Ideas???

Jordy

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Hi jordy. I don’t think ALL EM is caused by SFN just that many cases are. Have you had the sweat test mentioned in the artical? I had it and it was inconclusive. I had a few patches that were slow to sweet but did eventually. Problem was during the test I wasn’t very symptomatic during that time. My EM gets better and worse over months at a time and it took a few months to get in for the test. Wouldn’t YOU Know It I Was Having Less Symptoms At The Time Of The Test. If they had done it 2 months earlier or a month later I am sure they would find I had large areas that didn’t sweat AT all. MY HUSBAND was the first to notice that I wasn’t sweating at all at times.
Take care
Alina

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Thanks so much for posting these articles. What a great help.

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I have small fiber neuropathy confirmed by biopsy. My first biopsy was negative. It was repeated a year later and positive. My AFT was positive for decreased sweating but nothing else. If your last biopsy was more than a year ago and neg it may be worth repeating. Cornell in NYC now has a large bank of normative data to compare the sample to. Good luck!

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Thank you for your continued support and sharing of information
I was also tested by biopsy last month, still awaiting the results, will share when I get them
They also tested for fabry disease and that came back negative… I too am symptomatic on and off
THANKFULLY this seems to be a somewhat “off period” let’s hope and pray it lasts
God bless

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"A recent study showed that a predominantly small-fiber neuropathy underlies most cases of erythromelalgia"................. Hmmmmmm I know that the start of my issues was a small area , the tip of my right big toe, it didnt hurt but had a numb effect, I didnt notice it until I put my foot in my shoe, it felt like my sock was bunching up where my big toe was. It slowly over time got worse, spread into both feet, mostly in toes and the balls of my feet, pain started creeping in and the burning followed. For years I though it was some sort of nueropathy even though the neurologist said it was not your traditional neuropathy because I past all the test she did and the blood test. Maybe it started out as small fiber neuropathy and manifested into EM. One thing I never got was any tingling in my feet

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My understanding is the small-fiber neuropathy study is in its infancy, and the testing is hit and miss. If they take a biopsy it could be neg for SFN and a ½ inch away could be a positive area. I’ve had the biopsy and the sweat test (there are a few types). I would think the one they do at the Mayo Clinic would be the most comprehensible because it test the whole body. The study I saw from the Mayo Clinic a few years ago cited 88% of SFN in EM patients.


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Question--

If EM is the result of increased blood flow without accompanying oxygenation, has anyone heard that there could be relief if there is a way to increase oxygenation in the blood?

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Is there a cure of SFN ? I am asking because I think I have it together with EM, but if there is no cure I am not going to go through all the testing, just so I can have a second name for my discomfort/pain.

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I don’t know if there is a cure for it. I suppose it is like most everything else if you can cure what causes it will cure it. I know there is treatment for it but don’t quote me on this…I think the treatment is the same or similar for EM.
Good question Serena! I wonder if it dilated excessively to increase the oxygen and It doesn’t work because we don’t carry enough in our blood??? If that’s the case why would heat cause flares. Do we need more oxygen in heat? I know we need more during activity and activity causes it. What if you are on to something??? I think I shall ask my doctor. Maybe an oxygen saturation test while warm and or with activity ?? I think first I will buy one from the drug store and try it at home when I am flaring. I will write what I find out.just curious… thank you for thinking of it!

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Alina--

You can purchase a blood oxygen measurement device from the drug store?

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Hi dkel,

Well it just goes to show that there are caring doctors in this world. Or are they all living in A del aide? Actually I have mostly very good doctors. I suffer one or two doctors who have attitude. And I did have to fire one once. It was most satisfying. I do lament to my hubby - the builder - that had I known this was going to happen to me I would have made it my business to become a doctor, or at least marry one.

Blue

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Thank U so much for posting this. This information will not only help many of us to know which direction to look, but also provides a well respected source of information to show our doctors.

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Thank you Serena. I am going to purchase one today and start keeping a log to see if there is anything there. I know they go on your finger but I wonder if it will also work on your toes during a foot flare. I get flares in my hands too but lately they have been more frequent in my feet.



Serena said:


Alina--

You can purchase a blood oxygen measurement device from the drug store?

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Hi Guys,

This very compassionate USA Neurologist happy to share his article on SFN and diagnosis via skin biopsy.

Interesting and much needed information.

http://practicalneurology.com/2009/10/PN1009_06.php

233-DiagnosingSFNviaskinbiopsy.pdf (45 KB)
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thank you Mads . This is one of the few tests I haven't had done yet so I will be sure to speak with my doctor about it.

Thank you too Fixme for starting this a while ago.

Take care,

Alina

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Just diagnosed with SFN and didn’t quite know what to make of it.
THANK YOU !!! This post couldn’t come at a better time !