Erythromelalgia: a Red Neuralgia.

Acta Neurologica Taiwanica Vol 25 No 1 March 2016 A 35-year-old woman presented with acute onset of left foot numbness on awakening in the morning two days ago, followed by burning pain at night before sleep. The pain could be relieved by taking analgesics, but the numbness persisted. She had similar attack over the distribution of left ulnar nerve half a year ago. The presentation was acute onset numbness of the ulnar two fingers and weakness of left hand. The patient reported mild local heat but no erythema was noted. Compressive neuropathy was impressed after nerve conduction study (NCS), but the recovery was poor. She denied exposure to chemicals or toxins. Family history of systemic lupus erythromatosus (SLE) was noted. Physical examination showed erythema and elevated skin temperature of left sole (Figure 1A) and mild swelling of left foot. The patient was not aware of the skin changes and denied feelings such as local heat or swelling. Neurological examination was unremarkable except left claw hand deformity and weakness. NCS was done several hours later, and the skin changes disappeared before the study. The study confirmed the diagnosis of left ulnar neuropathy with low compound motor action potential (CMAP). It also revealed a borderline low CMAP of left tibial nerve while the sensory studies were normal. Under the impression of erythromelalgia with family history of SLE, laboratory tests including the hemogram, serum vitamin B12 and folic acid levels, thyroid function, erythrocyte sedimentation rate (ESR) and autoimmune markers were checked, and the results were Pictorial Neurological Disease