Unusual renal manifestations in a girl with hyperthyroidism

A 16-year-girl, a known case of hyperthyroidism since last 6 months, presented to the emergency with complaints of acute gastroenteritis of 5 days duration. At admission the child was found to be hypovolemic with acidotic breathing, which was thought to be due to dehydration. However, despite fluid correction she remained acidotic. A diagnosis of distal renal tubular acidosis (RTA) was suspected when her renal scan, for the cause of metabolic acidosis, revealed nephrocalcinosis. This was later confirmed by relevant investigations. She was started on treatment for distal RTA on which she symptomatically improved. The association of distal RTA and thyroid disorders is rarely reported in children. Till date there is only one report of distal RTA and hypothyroidism, but none with hyperthyroidism in this age group. The authors chose to report this case to highlight the fact that one should have a high index of suspicion for renal tubular disorders in children with thyroid hormone abnormalities, as these are treatable conditions if diagnosed early.