Introduction: Adrenal suppression secondary to long-term steroid therapy is a known risk and this can mask the evolution of primary adrenal insufficiency.
Case report: A 6 years old girl with background of recurrent oral ulcers (probable mucocutaneous Behcets), Alpha-1-Antitrypsin deficiency, Bronchiectasis, on long-term oral Prednisolone treatment, was noted to have hyponatraemia (Na=122 mmol/l) and hyperkalaemia (K=6.6 mmol/l) during an inter-current illness and referred to the local Endocrine team. Clinically, she was noted to have Cushingoid features with significant growth concerns. Investigations confirmed Adrenal Insufficiency likely secondary to adrenal suppression due to long-term Prednisolone (Hydrocortisone (HC) equivalent dose of 30 mg/m2 per day). Following MDT discussion, it was agreed to change Prednisolone to HC with intention of slowly weaning off steroid whilst managing oral ulcers with non-steroidal preparation. Electrolytes normalised on HC. 4 months later, while on weaning dose of HC (=15 mg/m2 per d), she was noted to have hyponatraemia (Na=129 mmol/l) and hyperkalaemia (K=6.1 mmol/l) during a diarrhoea episode which failed to correct despite stress doses of HC. She was commenced on Fludrocortisone (FC) and electrolytes normalised within 24 hours. 2 months later, whilst on weaning regime HC (8 mg/m2 per d) and FC, repeat investigations were in keeping with Primary Adrenal Insufficiency (see table). She continues HC and FC replacement doses and remains well.
Table summarising the results:
|HC Dose (mg/m2 per d)||30||15||8|
|Renin (mIU/l)||538||sample insufficient||305.9|
|Low dose synacthen test|
|0 min (nmol/l)||250||<25|
|20 min (nmol/l)||205||<25|
|30 min (nmol/l)||219||<25|
|Management||Weaning HC||FC commenced||Continue FC and HC|
Discussion: This case highlights that evolving primary adrenal insufficiency can be masked by adrenal suppression from long-term steroid treatment. Need for mineralocorticoid supplement whilst on HC in a case treated for adrenal suppression was the first clue which alerted of the possibility of primary adrenal insufficiency as the underlying diagnosis.
22 - 24 Nov 2017
British Society for Paediatric Endocrinology and Diabetes