Novel presentation of autoimmune polyglandular syndrome II i
Providers should remain vigilant of autoimmune polyglandular syndrome type II in the context of persistent low blood sugar in type I diabetes. Correction of adrenal insufficiency is key for regulation of blood sugar and thyroid function.

An 11-6/12 year old Tanner stage II female presented in February 2014 with polyuria, polydipsia, and a 10-pound weight loss. She had no family history of endocrinopathy on either side of her family. Laboratory studies at this time revealed new-onset type I diabetes mellitus. She was started on insulin at this time. She began to develop significant hypoglycemia on insulin and was taken off entirely in March 2014.

In May 2014, she was persistently losing weight despite good oral intake and experiencing a decline in her academic performance. During this time, blood sugars tested at home were found to be normal. Physical examination at this time revealed mild thyromegaly and flattening of growth curves. A diagnosis of autoimmune polyglandular syndrome type II was made at this time with the full triad of Addison's disease, Hashimoto's thyroiditis, and type 1 diabetes mellitus. Treatment was initiated with fludrocortisone 0.05 mg daily and hydrocortisone 9.4 mg/m2/day.

Once control of Addison's was achieved, levothyroxine was started. Following treatment with fludrocortisone, hydrocortisone, and levothyroxine, she returned to her baseline academic performance as an A-student. She is currently well controlled as of January 2021 on her regimen of hydrocortisone 9.2 mg/m2/day, fludrocortisone 0.05 mg daily, levothyroxine 44 mcg daily, basal-bolus insulin therapy delivered by insulin pump, and continuous glucose monitoring. She has additionally been screened for additional autoimmune conditions, including pernicious anemia, celiac disease, and myasthenia gravis, none of which are positive as of January 2021. She has not required any immune-regulatory therapy to this point.

In 2017, the patient's biological mother presented at age 42 with new onset fatigue, positional lightheadedness, weight loss, nausea, abdominal pain, and skin hyperpigmentation. She was found to have thyroid nodules at that time. Laboratory results in May 2017 revealed ACTH of 1127 pg/ml, Cortisol 9.2 ?g/dl, Aldosterone less than 3 ng/dl, and Adrenal antibodies 110.5 ?/ml. She has since been diagnosed by her endocrinologist with adrenal insufficiency in the setting of potential APS type II and treated accordingly. As of April 2021, thyroid function tests have been within normal limits and she has not developed diabetes mellitus, nor has she required any immune-regulatory therapy.