SAT-430 - Spontaneous Resolution of Steroid dependency in Addison's disease

Introduction
Addison’s disease is a rare primary adrenal insufficiency with an estimated incidence of 4.4–6.2 per million per year and a prevalence of 82–140 per million. Lifelong glucocorticoid replacement is considered the standard of care, and spontaneous recovery of adrenal function is exceptionally rare. We present a case of spontaneous remission after 11 years of steroid dependency and review the existing literature.
Case Presentation
A 52-year-old female presented in 2014 with a serum cortisol of 0.4 µg/dL following a course of corticosteroids for asthma. She reported intermittent steroid use two to three times per year for episodic asthma exacerbations. An ACTH stimulation test performed after hydrocortisone taper demonstrated a subnormal response: baseline cortisol < 0.2 µg/dL, rising to 2.8 µg/dL at 30 minutes and 3.8 µg/dL at 60 minutes. Serum 21-hydroxylase antibodies were elevated, confirming autoimmune etiology. She was initiated on hydrocortisone 10 mg each morning and 5 mg each evening. Renin activity was 1.0 ng/mL/hr, and mineralocorticoid replacement was not required. Electrolytes remained consistently normal throughout follow-up.
Beginning in April 2019, morning cortisol became detectable at 2.3 µg/dL and subsequently rose to 7.3 µg/dL later that year, prompting a gradual taper of hydrocortisone. In January 2020, ACTH was 52 pg/mL with cortisol of 9.0 µg/dL; however, a symptomatic flare of fatigue and weakness necessitated a temporary dose increase to 10 mg daily, which was maintained through the COVID-19 pandemic. By July 2024, cortisol had reached 9.5 µg/dL with ACTH of 68 pg/mL while on 10 mg hydrocortisone. A structured six-month taper was initiated per patient preference. Hydrocortisone was successfully discontinued in February 2025, with a morning cortisol of 10.8 µg/dL, ACTH of 36 pg/mL, and normal electrolytes. The patient has remained asymptomatic, with no hypotension, weight loss, or fatigue.
Discussion
This case illustrates that spontaneous recovery of adrenocortical function, while exceedingly rare, can occur in autoimmune Addison’s disease. A review of the literature identifies four previously reported cases — three in adults and one in a pediatric patient — with durations of steroid dependency ranging from 3 to 16 years. In our patient, dependency lasted approximately 11 years. Across all reported cases, recovery was identified incidentally through routine cortisol monitoring, which prompted careful, supervised steroid withdrawal. These cases collectively suggest that periodic assessment of morning cortisol — at minimum on an annual basis — is warranted in all patients with Addison’s disease, as it may identify the rare individual who has recovered sufficient adrenal function to safely discontinue replacement therapy.

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