Suellen Walker1, Kirsty Keen1, Luke Arthur1, Richard Howard1
1) United Kingdom
Erythromelalgia is a rare but severe form of neuropathic pain in children [1]. Episodic pain and redness can occur bilaterally in the hands, feet, and/or ears. Pain is burning in nature, exacerbated by heat and exercise, and relieved by cooling. Genetic mutations affecting the SCN9A or SCN10A gene that produce gain of function mutations of voltage-gated sodium channels have been implicated [2]. Clinical phenotypes have been described in adults with onset of erythromelalgia during childhood [3], but there is limited information regarding management during childhood.
We reviewed our current cohort of erythromelalgia patients managed and/or referred to the GOSH Pain Clinic and conducted a systematic literature review of erythromelalgia in children. The following data was obtained: i) age of onset; ii) presenting symptoms; iii) aggravating and relieving factors; iv) treatment type and response; and v) genetic testing results (if available).
Patients were stratified into the following groups: i) symptomatic and positive genetic test; ii) typical presentation and negative genetic test; and iii) atypical presentation and negative genetic test. Similarities and differences across groups are highlighted. For those with confirmed genetic changes, severity of symptoms and age of onset for mutations at different sites is compared.
Erythromelalgia is a rare but severe form of episodic neuropathic pain in children. Ongoing collection of cohort data will assist further identification of diagnostic features and help inform management.
Funding support Great Ormond Street Hospital Children's Charity
Clinical collaborators: Dr Alison Kelly, Bristol; Dr John Goddard, Sheffield
[1] Howard RF, Wiener S, Walker SM. Neuropathic pain in children. Arch Dis Child 99:84-89;2014.
[2] Waxman et al. Sodium channel genes in pain-related disorders: natural history, clinical phenotype and somatosensory profile. Lancet Neurol 13:1152-1160;2014.
[3] McDonnell et al. Inherited erythromelalgia due to mutations in SCN9A: natural history, clinical phenotype and somatosensory profile. Brain 139:1052-106;2016
