Case Presentation: A 37 -year-old female with a past medical history of obesity status post bariatric surgery and hypothyroidism presented to ED for evaluation of progressive generalized weakness. The patient had a recent couple of hospital admission for recurrent rhabdomyolysis. During the hospitalization, she was found to have elevated creatine kinase (CK) level, hypokalemia, and metabolic acidosis. Though CK level improved to some extent, it remained elevated despite intravenous hydration that prompted evaluation for other secondary causes of rhabdomyolysis. She also reported dryness of the eyes and mouth, joint discomfort, and stiffness lasting more than 2 hours. The rheumatologist evaluated the patient, and SSA/Ro Ab was strongly positive. She was diagnosed with Sjogren’s syndrome based on clinical features and laboratory data. The patient was also found to have AKI, hypokalemia, and hyperchloremic metabolic acidosis. CK was 1847 U/L, serum potassium 3.3 mmol/L, Chloride 112 mmol/L, CO2 18 mmol/L. The nephrologist evaluated the patient and hyperchloremic metabolic acidosis was likely secondary to distal Renal Tubular Acidosis (RTA type 1) associated with Sjogren’s syndrome. She was started on prednisone and mycophenolate with the improvement of rhabdomyolysis, hypokalemia, and metabolic acidosis.
Discussion: Rhabdomyolysis is caused by the rapid breakdown of skeletal muscle fibers that results in the release of toxic muscle cell content into systemic circulation. The clinical presentation of rhabdomyolysis varies from an asymptomatic elevation of serum creatinine kinase (CK) to cardiac arrhythmia, acute kidney injury, and disseminated intravascular coagulation. The most common causes of rhabdomyolysis are illicit drug abuse, certain medications, and trauma. Infection, electrolyte imbalances, endocrine disorders, and metabolic myopathies are among the other less frequent causes. In the case of recurrent rhabdomyolysis and the absence of other etiologies, Sjogren’s syndrome should be considered as one of the differentials. Sjogren’s syndrome is a chronic autoimmune disease and usually responds to treatment with corticosteroids and immunosuppression. Sjogren’s syndrome can have renal involvement as a part of the extra glandular manifestation of the disease. Renal involvement in Sjogren’s syndrome can be interstitial nephritis, distal RTA, proximal RTA, nephrogenic diabetes insipidus, glomerular diseases, or renal failure. In Sjogren’s syndrome, there is lymphocytic infiltration in the exocrine glands. RTA is thought to be resulting from lymphocytic tubulointerstitial infiltrates. Hypokalemia is the most common electrolyte abnormality in patients with distal RTA. Hypokalemia can cause muscle ischemia and, severe potassium depletion can lead to muscle necrosis and rhabdomyolysis. Any patient presenting with rhabdomyolysis, hypokalemia, and metabolic acidosis should be prompted for evaluation of possible underlying Sjogren’s syndrome.
Conclusions: Any patient who presents with rhabdomyolysis, hypokalemia, and metabolic acidosis should be evaluated for possible underlying Sjogren’s syndrome, so that appropriate treatment can be initiated in time.