Hypokalemic Quadriparesis as the Initial Presentation of Sjögren's Syndrome With Distal Renal Tubular Acidosis: A Case Report

A 44-year-old woman with long-standing hypothyroidism presented with sudden-onset flaccid quadriparesis preceded by distal limb paresthesia, progressing rapidly to respiratory compromise requiring intubation. Laboratory evaluation revealed severe hypokalemia with non-anion gap metabolic acidosis, elevated transtubular potassium gradient, and inappropriately alkaline urine, consistent with distal renal tubular acidosis (dRTA). In the emergency, correction of electrolytes, intravenous bicarbonate therapy, and supportive management led to rapid neurological improvement. Following stabilization, further evaluation revealed positive antinuclear antibody (ANA) and anti-Ro/SSA, anti-La/SSB, and Ro52 antibodies, confirming Sjögren's syndrome. The patient had no prior sicca symptoms. This case highlights that hypokalemic paralysis can be the initial presentation of Sjögren's syndrome through dRTA, preceding classical exocrine features. Early recognition and correction of metabolic derangements are crucial for preventing morbidity and facilitating the diagnosis of underlying autoimmune pathology.