Introduction Erythromelalgia is characterized by the triad of intense burning pain, marked erythema and increased skin temperature (1,2). Patients describe severe tingling or neuropathy-like pain (2) that usually affects the extremities: the feet more frequently than the hands (1,2) but also the ears and face (3). It is typically bilateral but can be unilateral, especially in secondary cases (1). Warming up, exercise and dependence on the legs are aggravating factors while cooling and elevation of the feet are relieving factors (3,4). It often has an intermittent course and the typical constellation of symptoms manifests itself only during exacerbations (1,2) which tend to occur late in the day (sometimes continuing even during the night), at certain temperatures. Frequent immersion in ice water, learned by patients as a soothing factor, can cause skin maceration, non-healing ulcers, infections, necrosis, and ultimately amputation (5). The onset of the disease may be gradual. Some cases remain mild for decades; others, about a third, have a rapid onset, begin to spread and become disabling within a few months (2,6). However, even mild cases can cause sleep interference and limit daily activities (1). Patients suffering from erythromelalgia have higher morbidity and mortality rates than the general population (2). Erythromelalgia is a rare clinical syndrome (4): the estimated incidence varies from 0.25/100,000 in Norway (7) to 1.3/100,000 in the USA (8). ). Women are affected more frequently than men (2.0 to 0.6 per 100,000) (8). It is classified as primary or secondary (1): primary erythromelalgia begins spontaneously at any age; secondary erythromelalgia is associated with other diseases (e.g. autoimmune diseases) (1). Primary erythromelalgia is category...... middle of paper ......, Chen Y, Xie NC, Wang LJ. Botulinum toxin type A for the treatment of trigeminal neuralgia: results of a randomized, double-blind, placebo-controlled trial. Cephalalgia: an international journal of headache 2012:32: 443-450.26. Simpson LL Identifying the characteristics that underlie the potency of botulinum toxin: implications for the design of new drugs. Biochimie 2000:82: 943-953.27. Guyer BM. Mechanism of botulinum toxin in the relief of chronic pain. Current Pain Review 1999:3:427-431.28. Aoki KR. Review of a proposed mechanism for the antinociceptive action of botulinum toxin type A. Neurotoxicity 2005:26: 785-793.29. Zhang L, Wang WH, Li LF, Dong GX, Zhao J, Luan JY, Sun TT. Long-term remission of primary erythermalgia with R1150W polymorphism in SCN9A after chemical lumbar sympathectomy. European Journal of Dermatology: EJD 2010:20: 763-767.