A Case of Salt-Wasting 21-Hydroxylase Deficiency With Resistance to Aldosterone due to Urinary Tract Infection

Urara Shimakawa,Keiichi Shigehara,Jun Mori,Kazutaka Ouchi,Yasuhiro Kawabe

doi:10.7759/cureus.11763

Urara Shimakawa, Keiichi Shigehara + Show 3 more

Open Access

https://doi.org/10.7759/cureus.11763

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Abstract

Classic salt-wasting 21-hydroxylase deficiency (21-OHD) often requires fludrocortisone (FC) replacement. However, the optimal dose of FC varies between patients and the dose needs to be adjusted depending on the degree of symptoms. Further, the aldosterone resistance due to urinary tract infections causes salt-wasting symptoms. We recently encountered a patient with 21-OHD who required up to 0.36 mg/day of FC in order to control hyperkalemia despite adequate hydrocortisone (HC) administration. This condition was presumed to be due to aldosterone resistance complications associated with urinary tract infections. Thus, if the initial treatment of 21-OHD with HC and FC is resistant, then one should consider complications that may cause aldosterone resistance, such as urinary tract infections.

Highlights

Classic salt-wasting 21-hydroxylase deficiency (21-OHD) often requires fludrocortisone (FC) replacement
We describe a case of a patient with 21-OHD complicated with urinary tract infections (UTI) who required up to 0.36 mg/day dose of FC in order to control hyperkalemia despite adequate hydrocortisone (HC) administration
We considered pseudohyperkalemia by blood sampling, acute renal failure, urinary obstruction, hemolysis, and drug-induced as the differential diagnosis of hyperkalemia, but all of them were denied

Summary

Introduction

21-hydroxylase deficiency (21-OHD) is the most common cause of congenital adrenal hyperplasia (CAH). Aldosterone resistance due to renal anomalies and/or urinary tract infections (UTI) can cause salt-wasting symptoms and this is called secondary pseudohypoaldosteronism (PHA) [3], and these conditions can occur together In such cases, this may mask the diagnosis of 21-OHD and make the initial treatment of 21-OHD difficult [4]. On Hospitalization Day 18, the serum potassium level was 7.5 mEq/L, and the transtubular potassium gradient (TTKG) and fractional excretion of sodium were 2.5 and 9.29 %, respectively. Since these findings suggested low aldosterone bioactivity, the dose of FC was increased to 0.36 mg/day. The patient has received regular follow-up care, but no notable findings and no electrolyte abnormalities have been observed to date, and the low TTKG improved to 7.4

Discussion

Conclusions

Disclosures

13. Hindmarsh PC