Hypokalaemia in Sjögren's syndrome: the missing piece.
A 58-year-old Chinese woman with well controlled type 1 diabetes mellitus presented with acute and progressive bilateral lower limb weakness. Investigations revealed severe hypokalaemia (1.3 mmol/L) and hypophosphataemia (<0.32 mmol/L) with rhabdomyolysis and electrocardiogram changes, without other concurrent biochemical abnormalities. Immediate intravenous and oral potassium and phosphate replacement was initiated with objective improvement in weakness with replenished electrolyte levels. Urine studies confirmed renal potassium wasting. Further history revealed frequent dental caries, xerostomia and recent weight loss. A computerised tomography scan showed atrophy of her salivary glands and a skin lesion biopsied by her GP in the past had been histologically characterised as anetoderma. The constellation of these findings and subsequent positive anti-SSA/SSB levels confirmed her diagnosis of primary Sjögren's syndrome (PSS). PSS has a wide spectrum of renal involvement and should be a differential diagnosis when investigating interstitial nephritis and electrolyte abnormalities, particularly in patients with coexisting autoimmune conditions.
National University Health System, Singapore.
Umer Farooq
UF
Khan
National University Health System, Singapore and National University Cancer Institute Singapore, Singapore.
Lee Chun
LC
Tsu
National University Health System, Singapore.
Kong-Bing
KB
Tan
National University Health System, Singapore.
Jingxiang
J
Huang
National University Health System, Singapore and Yong Loo Lin School of Medicine, National University Singapore, Singapore.
Audrey LiAnn
AL
Wong
D004562:Electrocardiography; D005260:Female; D006801:Humans; D007008:Hypokalemia / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D008875:Middle Aged; D011188:Potassium / Q000097:blood; D012859:Sjogren's Syndrome / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology
D011188:Potassium
Anetoderma; Sjögren’s syndrome; hypokalaemia