Sjögren's Syndrome With Distal Renal Tubular Acidosis and Hypokalemic Myopathy in Pregnancy: A Rare Case

Sjogren's syndrome may rarely present with distal renal tubular acidosis (dRTA), causing severe hypokalemia and myopathy. A 27-year-old primigravida at 15 weeks gestation presented with progressive proximal weakness and myalgia. Labs showed hypokalemia (1.76 mmol/L), hyperchloremic metabolic acidosis, and elevated creatine phosphokinase; urinary pH was 7.0. Anti-SSA/Ro and anti-SSB/La antibodies and a positive Schirmer's test confirmed primary Sjogren's syndrome. Although 16%-67% of Sjogren's syndrome patients present with renal involvement, hypokalemic myopathy due to dRTA in association with Sjogren's syndrome in pregnancy is a very rare presentation. Electromyography showed myopathic changes. Pregnancy likely worsened the electrolyte imbalance. This case highlights the need to consider autoimmune causes in pregnant patients with unexplained hypokalemia and weakness for timely diagnosis and management.