Novel clinical features of primary erythromelalgia; hypersensitivity to high salt concentrations as nociception and effects of sympathetic nerve blocks: a case report

Abstract

Background: Primary erythromelalgia (PE) is a rare disorder characterized by thermalgia. It is caused by mutations in voltage-gated Na channel (Nav) 1.7, which increase neuron excitability. The symptom of salt aversion in PE has not yet been reported. Case presentation: A 72-year-old woman had experienced severe frostbite since childhood. The patient developed redness as she warmed up at the age of 40 years and thermalgia as well as a salt aversion due to hypersensitivity to saltiness at the age of 70 years. She was diagnosed with PE. At the age of 72 years, we initiated treatment with stellate ganglion blocks (SGB) and epidural blocks. The symptom of salt aversion and pain in fingertips disappeared after treatment with SGB. Bilateral lumbar sympathetic ganglion blocks were performed to further attenuate pain in the tips of the toes, which disappeared after 2 months. Conclusions: We herein report the successful treatment of PE with hypersensitivity to saltiness.