title: Transient pseudohypoaldosteronism in infancy secondary to urinary tract infection.
abstract: OBJECTIVE
  Hyponatraemia with hyperkalaemia in infancy is a typical presentation of congenital adrenal hyperplasia. In the presence of pyelonephritis, the same biochemical picture can occur with transient type 1 pseudohypoaldosteronism (PHA-1) also termed type 4 renal tubular acidosis. Recognition of PHA-1 enables appropriate management thus avoiding unnecessary investigations and treatment. To improve awareness of this condition, we present a case series to highlight the clinical and biochemical features of PHA-1.
  
  
  METHODS
  A retrospective chart review of patients diagnosed with transient PHA-1 at a tertiary children's hospital in Western Australia was conducted.
  
  
  RESULTS
  Five male infants (32 days to 6 months) with transient PHA-1 were identified. Failure to thrive was the most common symptom with hyponatraemia on presentation. Two infants had antenatally diagnosed bilateral hydronephrosis and urinary tract infection (UTI) on admission. Two infants were treated for congenital adrenal hyperplasia and received hydrocortisone. All infants had UTI and required parenteral antibiotics. The condition was transient and hyponatraemia corrected by day 4 in all infants. There was no correlation between plasma sodium and aldosterone levels. The severity of PHA-1 was independent of the underlying renal anomaly. Four infants had hydronephrosis and vesicoureteric reflux. Surgical intervention was required in two infants.
  
  
  CONCLUSIONS
  PHA-1 may be precipitated by UTI or urinary tract anomalies in early infancy. Urine analysis should be performed in infants with hyponatraemia. Diagnosis of PHA-1 facilitates appropriate renal investigations to reduce long-term morbidity.
authors.affiliation: Department of Endocrinology and Diabetes, The University of Western Australia, Perth, Western Australia, Australia.|School of Child Health and Paediatrics, The University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Mary B
authors.initials: MB
authors.lastname: Abraham
authors.affiliation: Department of Nephrology, Princess Margaret Hospital, The University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Larkins
authors.affiliation: Department of Endocrinology and Diabetes, The University of Western Australia, Perth, Western Australia, Australia.|School of Child Health and Paediatrics, The University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Catherine S
authors.initials: CS
authors.lastname: Choong
authors.affiliation: Department of Endocrinology and Diabetes, The University of Western Australia, Perth, Western Australia, Australia.|School of Child Health and Paediatrics, The University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Vinutha B
authors.initials: VB
authors.lastname: Shetty
mesh_terms: D000450:Aldosterone / Q000097:blood; D005183:Failure to Thrive / Q000209:etiology; D005500:Follow-Up Studies; D006801:Humans; D007010:Hyponatremia / Q000175:diagnosis / Q000209:etiology; D007223:Infant; D008297:Male; D011546:Pseudohypoaldosteronism / Q000097:blood / Q000175:diagnosis* / Q000209:etiology / Q000652:urine; D012189:Retrospective Studies; D012964:Sodium / Q000097:blood; D014552:Urinary Tract Infections / Q000150:complications*
chemical_list: D000450:Aldosterone; D012964:Sodium
keywords: hyponatraemia; pseudohypoaldosteronism; type 4 renal tubular acidosis; urinary tract infection