Erythromelalgia: Incidence and clinical experience in a single centre in Sweden.

Background: Erythromelalgia (EM) incidence has not been well studied and there are only two studies published on this subject as far as we know. The aims are to study the incidence of this rare condition in the south of Sweden, to report the clinical experience from a single centre including characterisation of comorbidity and to report on prognosis. Patients and methods: Retrospective study of a population-based analysis of data from the southernmost part of Sweden corresponding to the median age of the patients (Statistics Sweden). The diagnosis of EM is based on the medical record reflecting the triad of redness, burning pain and increased temperature of the feet or hands or both. We evaluated the presence or absence of EM triad by recording the history, physical examination, laboratory analysis, cold provocation test and laser Doppler imaging, and by searching for any confounding disease in cases of suspected EM. Results: During a 10.5 year period we clinically identified 27 patients with EM. Median age was 49 [IQR (34 - 68)] years, 19 (70 %) were women. The mean delay from the onset of the symptoms to the time of diagnosis was 4.5 (SD ± 3.9) years. Gender and age adjusted incidence of EM for our region was calculated to be 0.36 per 100 000 persons per year. Three patients developed intraabdominal cancer during the follow up, but there was no mortality directed related to EM. Conclusions: The overall population-based incidence of erythromelalgia was 0.36 per 100 000 which is identical with a previous report in a Scandinavian population.