We present the clinical case of a woman in the fifth decade of life, argentina, who went to the Internal Medicine emergency room of a third level hospital for symptoms of myalgia and paresis in all four extremities, acute onset, progressive, with difficulty for the mobilization of members superior, standing and walking. Severe hypokalemia, metabolic acidosis, alkaline urinary pH, positive urinary anion GAP (ammonium excretion), hypocitraturia and hypercalciuria were diagnosed. Renal Tubular Acidosis (RTA) type I was diagnosed; acute renal failure was also noted, which corrected with the treatment and elevated creatine kinase (CK). In the anamnesis, the patient reported dry syndrome associated with arthralgias of years of evolution, so that complementary studies were carried out that supported the diagnosis of Sjögren’s Syndrome (SS).