Hypokalemic respiratory paralysis due to distal renal tubular acidosis as the presenting manifestation of Sjögren's syndrome

Abstract

Hypokalemic respiratory paralysis in Sjögren's syndrome (SS) with distal renal tubular acidosis (RTA) is very rare. In the literature, only five such cases have been reported. We report a 48-year-old lady, who presented with respiratory paralysis, bulbar weakness, and flaccid quadriplegia. She had severe hypokalemia (1.11 mEq/L), metabolic acidosis (pH = 7.09), hyperchloremia (120.8 mEq/L), and normal anion gap (11.2). An ammonium chloride test was consistent with the diagnosis of distal RTA. She recovered completely with potassium and alkali supplementations. Clinical features, positive Schirmer's test, and autoantibody screening were suggestive of diagnosis of SS. Hypokalemic periodic paralysis and respiratory involvement may occur as a first and rare complication of SS with distal RTA. Immunosuppressive therapy is not indicated except in the presence of systemic vasculitis. Potassium and alkali supplementations are the mainstay of the therapy. Patients with secondary hypokalemic periodic paralysis should be investigated for this possibility.