ERYTHROMELALGIA

Wednesday, 11 May 2005 16:08
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Erythromelalgia is a rare clinical syndrome, originally described by Mitchell in 1878.

The term is a descriptive one, comprising erythros (red), melos (extremity) and algos (pain). This denotes the triad of redness, increased temperature and pain usually in the extremities.

Alternative terms include erythermalgia and erythralgia.

Usually the phenomenon causes bouts of painful redness affecting the lower extremities, commonly symmetrically; other body parts can also be affected.

These attacks can be relieved by immersion of the affected part in cool water.

Erythromelalgia can be primary (occurs on its own) or secondary, in conditions of various types including neurological, vascular and haematological.

Pathophysiology:

Charkoudian ([1]) suggests that, like Raynaud's, erythromelalgia may well "represent cutaneous microvascular disorder..." related to "disorders of local and/or reflex thermoregulatory control of the skin circulation."

Davis et al. ([2]) found that 86% of patients with erythromelalgia when screened for autonomic reflex, had abnormal results, with abnormal axon reflex test, adrenergic function and cardiovagal function. 94% had abnormal sweating (absent or severely reduced).

Electromyography and nerve conduction tests in these patients were often abnormal and vascular function studies showed an average increase in toe skin temperature of 7.8 degrees C during symptoms, with a 10- fold increase in blood flow.

The authors of the study concluded,

"most patients with erythromelalgia have small-fiber neuropathy."

Various other aspects of the arachnoiditis syndrome raise the suspicion that small fibre neuropathy is an element of the condition. Another possibility is decreased sympathetic vasoconstrictor response to certain stimuli.

Mork et al. ([3]) suggested that microvascular arteriovenous shunting was a possible mechanism.

This means that the very small blood vessels are not functioning normally.

Arteriolar fibrosis and occlusion with platelet thrombi may occur, but not in all cases.

Platelets have been demonstrated to have abnormal hyperaggregability and platelet kinetic studies show decreased platelet survival, predominantly due to increased consumption.

Prostaglandins and cyclooxygenase appear to play an important role.

Sandroni et al ([4]) found that during symptoms, an increase in blood flow and skin temperature is accompanied by a paradoxical decrease in oxygen supply to the affected area; they stated that a high proportion of patients have a distal small fibre neuropathy as well as large fibre neuropathy.

In Type 2 diabetes, the ability of skin blood vessels to dilate is impaired, and this may contribute to increased risk of heat illness in these patients when exposed to elevated ambient temperatures.

The same might be true for arachnoiditis patients and could thus account for heat intolerance. However, in many arachnoiditis patients, there is frequent fluctuation between feeling cold and feeling over-warm, despite no change in ambient temperature.

Indeed, many seem to have problems with Raynaud's and it now seems that some individuals have erythromelalgia in addition, so that they experience fluctuation between cold, white extremities and hot, red, swollen and painful extremities.

Berlin and Pehr ([5]) presented a case of co-existent erythromelalgia and Raynaud's phenomenon, so, whilst rare, this combination is recognised.

This may affect not only the feet (most commonly), causing burning sensation (which may, or may not, differ somewhat, qualitatively, from the nerve-related burning in areas of reduced sensation) but also the hands and even the face. Ramirez and Kirsner ([6]) recently described a refractory case involving the ears.

Orstavik et al. ([7]) suggest that the pain experienced in erythromelalgia has a neuropathic component and certainly arachnoiditis patients may find it hard to distinguish between nerve-related burning, dyaesthetic pain and the ?thermal' burning pain of erythromelalgia.

Indeed, it is feasible that an individual may experience both of these pains at different times and some may describe them as different pains.

Causes:

Presentation:

In Davis' study, average duration of symptoms ranged widely from 1 month to 26 years, with a mean of 48 months. 7 patients had experienced symptoms since childhood. 97% had intermittent symptoms, the other 3% were constant.

Management:

Davis and Rooke ([9]) make the following suggestions:

"No treatment is consistently effective"

  1. patient education about the condition and avoidance of precipitating factors
  2. teach patients safe techniques to cool the affected parts
  3. pain control using the same range of medication as for neuropathic pain; aspirin can have idiosyncratic effects, being highly effective in some patients but ineffective in others. Surveys suggest that most patients find it ineffective. Davis and Sandroni ([10]) reported benefit from topical lidocaine patch and Kuhnert et al. ([11]) found lidocaine intravenous infusion followed by oral mexiletine gave prolonged remission. Capsaicin was not found beneficial in Davis's study and less than half of those tried on beta-blockers experienced benefit. Cohen ([12]) found that Gabapentin reduced symptoms effectively. Antihistamines are not helpful in most patients. He more recently conducted a small study based on his own experiences with the condition, using high dose oral magnesium. ([13]) 8 out of 13 patients reported improvement, 4 had no response and one worsened. Note that Aldrete is currently investigating magnesium as a therapy for arachnoiditis.
  4. Calcium antagonists such as diltiazem are strong vasodilators and do not seem beneficial in most patients and may indeed exacerbate the symptoms.
  5. note that some of these treatment have also been reported to exacerbate the condition: e.g. sympathetic blocks, epidurals, sympathectomy, nitroprusside infusion and calcium antagonists.
  6. control of secondary factors such as leg oedema etc.
  7. correct underlying medical condition
  8. direct patients to support groups such as: www.erythromelalgia.org  (email This e-mail address is being protected from spambots. You need JavaScript enabled to view it )

* myeloproliferative disorders: e.g. chronic myeloid leukaemia, polycythaemia rubra vera; erythromelalgia may precede the diagnosis; this group of patients tend to respond dramatically to aspirin, which may help towards a diagnosis. ([14]


 

[1] Charkoudian N. Mayo Clin Proc. 2003 May;78(5):603-12. Skin blood flow in adult human thermoregulation: how it works, when it does not, and why.

[2] Davis MD, Sandroni P, Rooke TW, Low PA. Arch Dermatol. 2003 Oct;139(10):1337-43. Erythromelalgia: vasculopathy, neuropathy, or both? A prospective study of vascular and neurophysiologic studies in erythromelalgia.

[3] Mork C, Asker CL, Salerud G, Kvernebo K J Invest Dermatol 2000; 114: 643-646 Microvascular arteriovenous shunting is a probable pathogenetic mechanism in erythromelalgia.

[4] Sandroni P, Davis MDP, Haper CM, Rogers RS, O'Fallon WM Rooke TW, Low PA J Clin Neuromuscular Disease 1999; 1(2): 57-63 Neurophysiologic and Vascular Studies in Erythromelagia: A retrospective analysis.

[5] Berlin AL, Pehr K. J Am Acad Dermatol. 2004 Mar;50(3):456-60. Coexistence of erythromelalgia and Raynaud's phenomenon.

[6]  Ramirez CC, Kirsner RS Am J Otolaryngol 2004 Jul-Aug; 25 (4) : 251-4 A refractory case of erythromelalgia involving the ears.

[7]  Orstavik K, Mork C, Kvernebo K, Jorum E Pain 2004 Aug; 110 (3): 531-8 Pain in primary eryhtromelalgia - a neuropathic component?

[8] Davis MDP, O'Fallon WM, Rogers RS, Rooke TW Arch Dermatol 2000;136: 330-336 Natural History of Erythromelalgia

[9] Davis MDP, Rooke T Current Treatment Options in Cardiovascular Medicine 2002; 4: 207-222 Erythromelalgia.

[10] Davis MD, Sandroni P Arch Dermatol 2002;138: 17-19 Lidocaine patch for pain of erythromelalgia

[11] Kuhnert SM, Phillips WJ, Davis MD Arch Dermatol 1999; 135: 1447-1449 Lidocaine and mexiletine therapy for erythromelalgia

[12] Cohen JS J Am Acad Dermatol 2000; 43: 841-847 Erythromelalgia: new theories and new therapies

[13] Cohen JS Ann Pharmacother2002; 36: 255-260 High-dose oral magnesium treatment of chronic, intractable erythromelalgia.

[14] Nardino RJ, Silber ALM emedicine article http://www.emedicine.com/med/topic730.htm  March 2004 Erythromelalgia