Erythromelalgia associated with acute diabetic neuropathy: an unusual condition.

Erythromelalgia is a syndrome characterized by erythema, burning pain and increased skin temperature of the affected extremities. It can be either primary (idiopathic) or secondary, but both forms require a critical temperature between 32-36 degrees C to provoke the crisis. Among the secondary forms, its association with diabetes mellitus is infrequent and its significance is little known. The histological studies have been fundamentally performed in patients with this syndrome affected by thrombocythemia; vascular thrombosis and fibromuscular intimal arteriolar proliferation were the prominent findings not corroborated in patients with the primary form. We studied one patient with acute diabetic neuropathy who developed erythromelalgia. We noted the absence of histopathological lesions, suggesting a disorder in vascular motility regulation favored by the severe neuropathy, without being able to discount a possible immunomediated mechanism. We describe the favourable evolution of the patient after treatment with aspirin and methysergide.