Idiopathic erythermalgia: a congenital disorder

Mutations in sodium-channel gene SCN9A cause a spectrum of human genetic pain disorders

The voltage-gated sodium-channel type IX alpha subunit, known as Na(v)1.7 and encoded by the gene SCN9A, is located in peripheral neurons and plays an important role in action potential production in these cells. Recent genetic studies have identified Na(v)1.7 dysfunction in three different human pain disorders. Gain-of-function missense mutations in Na(v)1.7 have been shown to cause primary erythermalgia and paroxysmal extreme pain disorder, while nonsense mutations in Na(v)1.7 result in loss of Na(v)1.7 function and a condition known as channelopathy-associated insensitivity to pain, a rare disorder in which affected individuals are unable to feel physical pain. This review highlights these recent developments and discusses the critical role of Na(v)1.7 in pain sensation in humans.

Thalamic stimulation as a treatment for primary erythromelalgia: technical case report

OBJECTIVE AND IMPORTANCE

We report the use of bilateral thalamic stimulation in a case of primary erythromelalgia with immediate and important pain relief for 3 years.

CLINICAL PRESENTATION

A 12-year-old boy experiencing primary erythromelalgia had a 4-year history of recurrent attacks of severe burning pain in both feet, accompanied by local reddening, swelling, and heating of the skin. The attacks were triggered by warmth and exercise. The pain was relieved only by elevation and cooling of the lower limbs, which he achieved by immersing his legs in a bucket of ice water, resulting in severe ulceration of the skin.

INTERVENTION

Because of the gradual aggravation of the signs and symptoms and resistance of the patient's condition to several medical therapies, the patient received spinal cord stimulation. The implants were removed twice because of recurrent infection. Finally, the patient was treated with bilateral electrical stimulation of the ventral posterolateral thalamic nucleus, which resulted in important pain control until 3 years later. The patient was able to avoid water immersions, and all ulcerations disappeared.

CONCLUSION

We conclude that thalamic stimulation was successful in this case of primary erythromelalgia.

Platelet-mediated microvascular inflammation and thrombosis in thrombocythemia vera: a distinct aspirin-responsive arterial thrombophilia, which transforms into a bleeding diathesis at increasing platelet counts

Erythromelalgia is the main, pathognomonic and presenting symptom in patients with essential thrombocythemia and thrombocythemia associated with polycythemia vera. Complete relief from erythromelalgic and acrocyanotic pain is obtained with the cyclooxygenase inhibitors aspirin and indomethacin, but not with sodiumsalicylate, dipyridamol, sulfinpyrozone and ticlopedine. Thus, cyclooxygenase metabolites are necessary for erythromelalgia to develop. Local platelet consumption in erythromelalgic areas became evident by the demonstration of arteriolar fibromuscular intimal proliferation and occlusions by platelet-rich thrombi in skin biopsies, by the findings of shortened platelet survival times, significant higher levels of platelet activation markers beta-thromboglobulin, thrombomoduline and increased urinary thromboxane B2 excretion in thrombocythemia patients suffering from erythromelalgia. Aspirin treatment of erythromelalgia in thrombocythemia patients resulted in the disappearance of the erythromelalgic, thrombotic signs and symptoms, correction of the shortened platelet survival times, and a significant reduction of the increased levels of beta-TG, PF4, TM and urinary TxB2 excretion to normal. Erythromelalgia is frequently preceded or followed by atypical transient neurologic, ocular or coronary ischemic symptoms, which specifically respond to low-dose aspirin or reduction of platelet counts to normal. The broad spectrum of acropareshesias, erythromelalgia and acrocyanotic ischemia together with the episodic and transient atypical TIAs and ocular or coronary ischemic symptoms are caused by spontaneous activation and aggregation of hypersensitive platelets in the end-arterial microvasculature involving the peripheral, cerebral and coronary circulation of thrombocythemia patients. These microvascular circulation ischemic disturbances in thrombocythemia vera already occur at platelet counts in excess of 400 x 10(9) l(-1). Low-dose aspirin is highly effective and safe in the cure and prevention of thrombotic and ischemic events and does not elicit bleedings at platelet counts below 1000 x 10(9) l(-1). Spontaneous hemorrhages usually occur at very high platelet counts far in excess of 1000 x 10(9) l(-1) (HT) due to an acquired von Willebrand factor deficiency at increasing platelet counts. At platelet counts between 1000 and 2000 x 10(9) l(-1), thrombosis and bleeding (ETT and HT) frequently occur in sequence or paradoxically and low-dose aspirin does prevent thrombotic complications but aggravates or may elicit bleeding symptoms. Reduction of the platelet count to below 1000 x 10(9) l(-1) by platelet lowering agents usually results in the disappearance of the bleeding tendency and improvement of the von Willebrand syndrome, but the thrombotic tendency persists as long as platelet counts are above the upper limit of normal.

The primary erythermalgia-susceptibility gene is located on chromosome 2q31-32

Primary erythermalgia is a rare disorder characterized by recurrent attacks of red, warm, and painful hands and/or feet. The symptoms are generally refractory to treatment and persist throughout life. Five kindreds with multiple cases of primary erythermalgia were identified, and the largest was subjected to a genomewide search. We detected strong evidence for linkage of the primary erythermalgia locus to markers from chromosome 2q. The highest LOD score (Z) was obtained with D2S2330 (Z(max) = 6.51). Analysis of recombination events identified D2S2370 and D2S1776 as flanking markers, on chromosome 2q31-32. This defines a critical interval of 7.94 cM that harbors the primary erythermalgia gene. Affected members within the additional families also shared a common haplotype on chromosome 2q31-32, supporting our linkage results. Identification of the primary erythermalgia gene will allow a better clinical classification of this pleomorphic group of disorders.

A case of erythromelalgia successfully controlled by systemic steroids and pentazocine--is it related to a unique subtype of neutrophilic dermatosis?

Erythromelalgia is a rare cutaneous disorder characterized by erythema, burning discomfort, and warmth of the extremities. Its form may be adult- or early-onset, and it may be further classified as idiopathic or secondary. Its pathogenesis and histopathologic findings have not yet been clearly defined. Various treatment modalities have been tried, but, for the idiopathic type, none has been successful. We present a case of adult-onset idiopathic erythromelalgia with unusual histopathological findings which showed a remarkable response to corticosteroids and pentazocine.

Cutaneous pathology in primary erythermalgia

Primary or idiopathic erythermalgia is characterized by recurrent, red, warm, and painful lower extremities. It arises at young age and persists throughout life because no treatment is available. We report the cutaneous pathology of affected skin lesions of three patients with primary erythermalgia. Biopsy specimens showed a mild perivascular mononuclear infiltrate, thickened blood vessel basement membranes, abundant perivascular edema, and moderate endothelial swelling. The thickened basal membrane of the blood vessels showed a laminar structure, and abundant perivascular edema and moderate endothelial cell swelling were evident. These histopathologic findings in primary erythermalgia appear to be nonspecific but allow diagnostic differentiation from erythromelalgia in which fibromuscular intimal proliferation and occlusive thrombi in the endarteriolar capillaries are apparent and from erythermalgia secondary to vasculitis. Histopathologic examination of affected skin lesions in patients with red, congested, warm, and painful burning extremities is a valuable tool in the diagnostic process.

Acute secondary erythermalgia and hypertension in children. Erythermalgia Multidisciplinary Study Group

We studied the clinical symptoms in nine children (seven females and two males; mean age 11.6 years) with severe but transient acute secondary erythermalgia. The classical symptoms at presentation were episodic attacks of painful burning hands and feet which felt warm with congested appearance of the feet. Each attack lasted for a mean period of 25 days (range from 6 to 56 days). The blood pressure was elevated in seven patients. Intravenous sodium nitroprusside was effective in ameliorating the symptoms with drop in blood pressure to normal in five patients; pizotifene, labetolol, prostaglandin E1 and hypnotherapy were effective in each of four separate cases. The episodes of acute secondary erythermalgia were transient in all and did not recur after a mean follow up period of 1.6 years. These cases suggest that acute secondary erythermalgia, however transient, is not rare and can be associated with mild to moderate hypertension which may respond to sodium nitroprusside. A greater awareness of this condition is necessary to make an accurate and timely diagnosis and institute appropriate therapy in order to prevent undue complications.

Verapamil-induced secondary erythermalgia

A 59-year-old man developed red, swollen and warm feet accompanied by intermittent burning pain during treatment for cardiac failure and arrhythmias with several drugs including verapamil. The condition gradually worsened until there was persistent disabling burning pain and severe erythema and swelling of the feet. Aspirin and other analgesics were ineffective in relieving the discomfort. Histopathology of punch biopsies showed a mild perivascular mononuclear infiltrate and moderate perivascular oedema. Within 2 weeks of stopping verapamil the burning pain, erythema, and swelling of the feet had resolved. The clinical features and subsequent course are consistent with a diagnosis of erythermalgia secondary to verapamil.

Erythromelalgia in thrombocythemia of various myeloproliferative disorders

Erythromelalgia is caused by platelet-mediated acral inflammation and arteriolar thrombosis in thrombocythemia in its primary form or associated with polycythemia vera. The prompt and lasting relief of burning pain by low-dose aspirin is a prerequisite for the diagnosis of thrombocythemic erythromelalgia. Here we extend observations on the occurrence of erythromelalgia in thrombocythemia associated with primary myelofibrosis, Philadelphia-chromosome positive micromegakaryocytic myelofibrosis, and myelodysplastic syndrome type II. It is concluded that erythromelalgia may occur in thrombocythemia of all variants of chronic myeloproliferative disease as well as myelodysplastic syndrome if platelet counts are sufficiently high.

Erythromelalgia: review of clinical characteristics and pathophysiology

Erythromelalgia is characterized by burning discomfort, warmth, and dermal erythema of the feet and/or the hands. Lowering the involved part and exposure to heat worsen symptoms, whereas elevation or cooling of the extremity relieves the discomfort. Several different subtypes of erythromelalgia have been documented and include an adult-onset form secondary to myeloproliferative syndrome-related thrombocytosis and an early-onset form that appears in childhood or adolescence and is idiopathic. A disturbed platelet function affecting the microvasculature has been implicated in thrombocythemia-related erythromelalgia. Importantly, manifestations of erythromelalgia often precede the onset of the myeloproliferative disease by several years. Therefore, the blood cell count should be monitored periodically in all adult patients with erythromelalgia. An abnormal hemoglobin, white blood cell, or platelet count or the presence of immature cells in the differential should prompt the physician to initiate a diagnostic evaluation for an underlying hematologic disorder. The symptoms of adults with erythromelalgia are markedly relieved after treatment with a single daily dose of acetylsalicylic acid. In contrast, childhood erythromelalgia appears without an underlying disorder, may be familial, and is resistant to treatment with aspirin.

Cutaneous manifestations in patients with essential thrombocythemia

In a retrospective study of 268 patients with essential thrombocythemia, related cutaneous manifestations were found in 58 (22%). In 27 cases (10%) the related skin lesions were present at the time of the primary diagnosis of essential thrombocythemia. Hematomas, ecchymoses, petechiae, or purpura occurred in 24 (41%) of the 58 patients. Fifteen patients (26%) had erythromelalgia, in 11 of whom it was the initial complaint. Livedo reticularis, recurrent superficial thrombophlebitis, ischemic complications with gangrene, leg ulcers, or ulcers on the toes were other manifestations. Urticaria occurred in two patients, and Raynaud's phenomenon and necrotizing vasculitis were each observed in one patient. Platelet function may be abnormal, and this was found in 13 of 19 patients studied, 9 of whom had spontaneous platelet aggregation. Knowledge of the cutaneous manifestations in essential thrombocythemia may lead to its earlier detection. Prompt diagnosis of essential thrombocythemia is important because treatment may prevent severe hemorrhagic or thrombotic events.