Acute Progressive Weakness in a Healthy Young Female

Case Presentation:

A 29‐year‐old, 5 week pregnant female was brought to the ER by her husband for progressive weakness. One day prior to presentation, the patient complained of leg cramps that by the following morning progressed to difficulty getting out of bed and she was unable to walk. Upon arrival to the ER, the weakness progressed to her upper extremities. She denied any difficulty breathing, but did relate a recent resolving upper respiratory infection with nonproductive cough. She denied any emesis, diarrhea, or history of previous episodes of weakness. On physical exam, distal lower extremity strength was minimal against gravity, and with weak bilateral hand grip. Initial concern was for Guillain‐Barre, however laboratory evaluation revealed a non anion gap metabolic acidosis with a potassium level of 1.6. EKG showed prolonged QT. Urinalysis was significant for a pH 8 and a positive urine anion gap, consistent with an intrinsic renal potassium wasting process. A diagnosis of distal type I renal tubular acidosis (RTA) was made. Further workup of the etiology for RTAwith auto‐immune serologies revealed a significantly elevated rheumatoid factor and positive anti‐Ro. The patient did not relate any symptoms of arthralgia, rash, or sicca symptoms. A presumptive diagnosis of early Sjogren syndrome with renal presentation of RTA and hypokalemia was made. Her weakness resolved completely with potassium and bicarbonate therapy.

Discussion:

This is a rare case of acute hypokalemic paralysis due to underlying distal RTA manifesting as a presentation of Sjogren syndrome. The progressive paralysis was a life threatening consequence of hypokalemia from potassium wasting due to RTA. Recognizing first the differential diagnosis of a common clinical finding of hypokalemia and subsequently making the diagnosis of RTA was key in repleting the patient's potassium quickly and appropriately. Furthermore, categorizing the RTA as distal type I, allowed for the appropriate evaluation that revealed positive serology for Sjogren syndrome. RTA is a well‐recognized extraglandular complication of adult Sjogren syndrome and there are several case reports describing the early presentation of renal symptoms prior to sicca symptoms of xerostomia and xerophthalmia. Furthermore, positive anti‐Ro and anti‐La serology is associated with increased risk for fetal heart block.

Conclusion:

Understanding that although weakness and hypokalemia are common inpatient complaints, interpreting this acid‐base disturbance in the appropriate clinical context allowed for the correct treatment of hypokalemia and a diagnosis of Sjogren syndrome as a cause for RTA in this patient.

Author Disclosure Block:

I. Krokos, None; T. Murphy, None; E. Kim, None; L. Cantor, None.