Hypokalemic Periodic Paralysis with Renal Tubular Acidosis in a Patient with Autoimmune Disorder

Hypokalemic periodic paralysis (HPP) is characterized by transient episodes of skeletal muscle weakness due to hypokalemia. It can arise from primary or secondary causes, with renal tubular acidosis (RTA) being a notable secondary etiology. Here, we present a case of HPP associated with RTA in a patient with an underlying autoimmune disorder, Sjögren syndrome.

A 29-year-old female presented with dry eyes and progressive weakness in both upper and lower limbs, leading to immobilization. Clinical examination revealed hypokalemia, normal anion gap metabolic acidosis, and alkaline urinary pH consistent with RTA type I. Immunological tests indicated markers suggestive of Sjögren syndrome. Treatment with potassium chloride resulted in motor function improvement.

The coexistence of HPP and RTA underscores the complex interplay between electrolyte disturbances and autoimmune pathology. Sjögren syndrome, an autoimmune exocrinopathy, can manifest with extraglandular involvement, including RTA. The diagnosis was supported by clinical, biochemical, and immunological findings.

This case highlights the clinical significance of recognizing HPP as a potential differential diagnosis in patients presenting with limb weakness, particularly in the context of autoimmune disorders such as Sjögren syndrome. Early diagnosis and appropriate management are crucial for preventing life-threatening complications associated with HPP and optimizing patient outcomes.