Endocrine Abstracts

Background: We present a case in which a diagnosis of Addison’s disease was missed due to misinterpretation of short synacthen test (SST). This patient was also found to have Polyglandular Syndrome Type 2 (APS-2) after further tests were performed.

Clinical case: A normally fit and well 28-year-old Caucasian man presented to hospital with a few days history of general malaise and a syncopal episode. On admission, patient was hypotensive and tachycardic. Admission bloods showed hyponatraemia, hypokalaemia, acute kidney injury and raised inflammatory markers. The diagnosis of Addisons’s disease was suspected. Patient was given hyperkalaemia treatment, intravenous fluids, broad spectrum intravenous antibiotics and intravenous hydrocortisone. Patient markedly improved over the next few hours. On the day after, SST was performed without holding off patient’s morning dose of hydrocortisone. Therefore, his SST results showed good response. This was misinterpreted as ruling out adrenal deficiency. He was hence discharged without hydrocortisone replacement. Two weeks later, patient was re-admitted to hospital with similar presentation. SST was repeated before patient’s morning dose of hydrocortisone. This time, it demonstrated flat response. This finally confirmed patient’s diagnosis of Addison’s disease. Patient was started on oral hydrocortisone and fludrocortisone. As patient’s TFT and TPO antibodies results showed evidence of autoimmune hypothyroidism, he was also started on thyroxine a week after discharge. Patient was followed up in clinic six weeks later and had remained well. Further blood tests were performed to screen for other conditions associated with APS-2. Patient was also found to have probable underlying pernicious anaemia.

Conclusion: It is important to correctly perform and interpret SST results to prevent missing the diagnosis of Addison’s crisis in clinical practice. As Addison’s disease can co-exist with other autoimmune conditions, screening for other autoimmune disorders should be performed to enable early identification of any other underlying conditions.