Endocrine Abstracts

Baseline cortisol values may not necessarily rule out Addison’s disease. We report a case with vague symptomatology,normal coritsol baseline values with high index of suspicion and positive low dose synacthen test which lead up to the diagnosis. Young boy age 9 presented with low serum sodium levels and intermittent concern with abdominal symptoms, exhaustion and altered behaviour. He had normal baseline pituitary function including cortisol of 223 that decreased to 156 (133–537 nmol/l) over the next month. Serum and urine osmolality were normal. Kidney function screen was normal. Gas had a borderline low bicarbonate around 15–19 and Kidney ultrasound scan was normal. Protein, full lipid profiles and thyroid function was normal. The serum sodium level ranged between 120 and 132 needing around 10 (600 mg) tablets of slow sodium chloride a day. No history of polydipsia and he was euvolumeic. No history of travel or drugs. Calcium creatinine ratio was normal. Blood glucose levels normal. He felt much better with sodium supplements but continued to have intermittent problems with abdominal symptoms and concerns with behaviour needing overnight admissions. MRI brain and spine was normal. Continuing concerns with hyponatremia dependent on supplements and altered behaviour over 7 weeks caused a lot of anxiety with the family, with repeated admissions. Low dose synacthen test was completed that was positive. Serum rennin levels were very high >4000(17.8–102.9). ACTH was high at 1979, 17 OHP levels were normal and aldosterone levels were <18 (140–2220). Very long chain fatty acids was normal. Sodium was monitored on an ambulatory basis until the adrenal cortex antibodies came back positive with a diagnosis of autoimmune Addison disease. Symptoms completely resolved with hydrocortisone and fludrocortisone treatment. The case was unusual due to the fact that the symptoms were not particularly worrying other than mild weakness, abdominal symptoms, altered behaviour with low serum sodium levels and normal baseline morning cortisol levels. With current working within NHS shift patterns it is imperative that communication lines are clear with continuing high index of suspicion that led to a potentially life threatening diagnosis.