Sympathetic blocks in the treatment of erythromelalgia: case series

BACKGROUND: Erythromelalgia (EM) is a rare, debilitating condition characterized by episodic burning pain, erythema, and increased skin temperature, typically affecting the distal extremities. EM significantly impairs quality of life (QoL) and may lead to functional disability. Although its pathophysiology is not fully understood, proposed mechanisms include small fiber nerve dysfunction and dysregulation of the sympathetic nervous system. Management remains challenging, with no universally effective treatment currently available. CASE PRESENTATION: We present three patients with refractory lower extremity erythromelalgia treated with lumbar sympathetic block (LSB). All patients had chronic treatment-refractory symptoms and had failed multiple prior treatments, including neuropathic medications and conservative measures. Bilateral L3 LSBs were performed using a standardized approach. Two patients experienced substantial symptom improvement, with reported reductions in pain intensity and a prolonged benefit lasting several months. One patient demonstrated partial, short-term improvement. Repeated LSB procedures were performed in cases of symptom recurrence. CONCLUSION: In this retrospective case series, LSB was associated with symptomatic improvement in selected erythromelalgia patients, potentially by modulating sympathetic activity and regional blood flow. However, given the small sample size and retrospective design, no conclusions regarding efficacy can be drawn. Further studies are needed to better define patient selection criteria and long-term outcomes.