Hypokalaemic Periodic Paralysis in a Patient with Rheumatoid Arthritis: A Case Report

Abstract

Periodic skeletal muscle weakness in Hypokalaemic Periodic Paralysis (HPP) can lead to respiratory muscle failure and mortality. This muscle weakness is caused by decrease in serum potassium levels (<3.5 mmol/dL), which can be either primary or secondary. The present case report describes an unusual presentation of HPP in a 37-year-old female with known Rheumatoid Arthritis (RA), who complained of sudden-onset quadriparesis. Upon evaluation, the patient was diagnosed with hypokalaemia, and treatment for this condition resulted in marked improvement of the paresis. While there are several deadly neuromuscular causes of quadriparesis, dyselectrolytaemia should be evaluated and treated, especially in patients with autoimmune diseases. In such patients, hypokalaemia could be due to medications such as corticosteroids or immunosuppressants like methotrexate, or as a result of underlying renal tubular acidosis. The present report adds to the scant literature on the association between RA and HPP through detailed clinical examination, laboratory investigations, and successful management with potassium supplementation.