{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,16]],"date-time":"2026-10-16T18:47:37Z","timestamp":1792176457264,"version":"4.4.0"},"reference-count":27,"publisher":"Oxford University Press (OUP)","issue":"2","license":[{"start":{"date-parts":[[2026,1,1]],"date-time":"2026-01-01T00:00:00Z","timestamp":1767225600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/academic.oup.com\/pages\/standard-publication-reuse-rights"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,6,29]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Primary erythromelalgia (PEM) is a rare autosomal dominant disorder characterised by episodic erythema and burning pain of the extremities, typically triggered by exercise or fatigue. PEM usually begins in childhood and is caused by gain-of-function variants in SCN9A, which encodes the voltage-gated sodium channel Nav1.7. The disease concept of PEM, however, is largely unrecognised among rheumatologists. Here, we report a 20-year-old woman who had experienced recurrent burning pain and redness of the extremities since around age 10. She also exhibited livedo-like rash, leukopenia, and hypocomplementemia and tested positive for antinuclear antibodies. Nerve conduction studies showed abnormalities interpreted as compatible with multifocal mononeuropathy. Based on these findings, she was diagnosed with systemic lupus erythematosus and treated with 20\u00a0mg of prednisolone; however, the painful erythema of the extremities did not improve. Given a family history of similar episodic symptoms in her father, PEM was suspected. Genetic testing identified a heterozygous SCN9A p.G856D variant, supporting the diagnosis of autosomal dominant PEM. Direct immunofluorescence\/lupus band testing of the biopsied lower-leg lesion was interpreted as negative. This case highlights that SCN9A-associated PEM may present with lupus-like cutaneous erythema in young patients, potentially leading to misdiagnosis and ineffective immunosuppression. PEM should be considered in patients with childhood-onset, trigger-induced painful erythema of the extremities, particularly when there is family history or poor response to steroids.<\/jats:p>","DOI":"10.1093\/mrcr\/rxag089","type":"journal-article","created":{"date-parts":[[2026,10,2]],"date-time":"2026-10-02T11:46:00Z","timestamp":1790941560000},"source":"Crossref","is-referenced-by-count":0,"title":["Primary erythromelalgia associated with an SCN9A variant can mimic systemic lupus erythematosus in skin manifestations: A case report"],"prefix":"10.1093","volume":"10","author":[{"given":"Atsuko","family":"Tomikawa","sequence":"first","affiliation":[{"name":"Department of Allergy and Clinical Immunology, Graduate School of Medicine, Chiba University , Chiba 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,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Makoto","family":"Yamamoto","sequence":"additional","affiliation":[{"name":"Department of Dermatology, Chiba University Hospital , Chiba ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rena","family":"Oguma","sequence":"additional","affiliation":[{"name":"Department of Dermatology, Chiba University Hospital , Chiba ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yoshihide","family":"Okano","sequence":"additional","affiliation":[{"name":"Department of General Medicine, Chiba University Hospital , Chiba ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eri","family":"Sato","sequence":"additional","affiliation":[{"name":"Department of General Medicine, Chiba University Hospital , Chiba 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Clinical Immunology, Graduate School of Medicine, Chiba University , Chiba ,","place":["Japan"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"286","published-online":{"date-parts":[[2026,10,6]]},"reference":[{"key":"2026101614015709700_ref1","doi-asserted-by":"publisher","first-page":"86","DOI":"10.1590\/abd1806-4841.20187535","article-title":"Erythromelalgia: a cutaneous manifestation of neuropathy?","volume":"93","author":"Leroux","year":"2018","journal-title":"An Bras Dermatol"},{"key":"2026101614015709700_ref2","doi-asserted-by":"publisher","first-page":"171","DOI":"10.1136\/jmg.2003.012153","article-title":"Mutations in SCN9A, encoding a sodium channel alpha subunit, in patients with primary erythermalgia","volume":"41","author":"Yang","year":"2004","journal-title":"J Med Genet"},{"key":"2026101614015709700_ref3","doi-asserted-by":"publisher","first-page":"785","DOI":"10.1002\/ana.20511","article-title":"Erythromelalgia: a hereditary pain syndrome enters the 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