Distal renal tubular acidosis presenting with an acute hypokalemic paralysis in an older child with severe vesicoureteral reflux and syringomyelia: a case report

BACKGROUND: Distal renal tubular acidosis (dRTA) is the most common type of renal tubular acidosis (RTA) in children. Pediatric dRTA is usually genetic and rarely occurs due to acquired issues such as obstructive uropathies, recurrent urinary tract infections (UTIs), and chronic kidney disease (CKD). Although persistent hypokalemia frequently occurs with dRTA, acute hypokalemic paralysis is not frequently reported, especially in older children. CASE PRESENTATION: An eight-year-old girl presented with an acute first episode of paralysis. A physical examination revealed normal vital signs, short stature consistent with her genetic potential, and decreased muscle strength of her upper and lower extremities. Preexisting conditions included stage 4 CKD due to recurrent UTIs, severe vesicoureteral reflux and bilateral hydronephrosis, neurogenic bladder, and multisegment thoracic syringomyelia. Her laboratory work-up revealed hypokalemic, hyperchloremic metabolic acidosis with a normal anion gap. She also had a urine osmolal gap of 1.9 mOsmol/kg with a high urine pH. Intravenous potassium replacement resulted in a complete resolution of her paralysis. She was diagnosed with dRTA and discharged with oral bicarbonate and slow-release potassium supplementation. CONCLUSIONS: This case report highlights the importance of considering dRTA in the differential diagnosis of hypokalemic acute paralysis in children. Additionally, in children with neurogenic lower urinary tract dysfunction and recurrent UTIs, early diagnosis of spinal cord etiology is crucial to treat promptly, slow the progression of CKD, and prevent long-term complications such as RTA.