Newly diagnosed T1 diabetes presenting with hypoglycemia due to simultaneous co-existence of Addison disease.

Type 1 diabetes mellitus (TIDM) classically presents with symptomatic hyperglycemia and many patients develop diabetic ketoacidosis prior to their diagnosis. However, non-classical presentation or co-presentation with associated diseases may delay diagnosis or lead to challenges in acute, clinical management. An 18-yr-old girl presented to hospital with severe, symptomatic hypoglycemia. Clinical history and serum electrolyte concentrations suggested a diagnosis of adrenal insufficiency. She remained hypoglycemic until glucocorticoid replacement was commenced, at which point she developed persistent hyperglycemia requiring insulin therapy. Subsequent follow up confirmed the diagnosis of Addison's disease (AD), the treatment of which unmasked co-existing type 1 diabetes. Autoimmune diseases often cluster together in affected patients and first-degree relatives. Approximately 1 in 200 patients with T1DM develop AD. However, months or more commonly years usually elapse between the presentation of different autoimmune conditions. The co-diagnosis T1DM and AD in the acute setting is rare. Moreover, the first presentation of T1DM with severe hypoglycemia is even more exceptional. This case highlights the need for vigilance during the acute, emergency management of patients with autoimmune conditions and, in particular, to consider the possibility of concurrent antibody-mediated diseases which may need to be addressed during resuscitation.