SUN-426 Negative antibody autoimmune adrenal insufficiency in the elderly

Abstract Disclosure: J.L. Andrade Piedra Avila: None. M. Luis Lam: None. Autoimmune adrenalitis is a rare cause of adrenal insufficiency in patients over 60. The non-specific symptoms of adrenal insufficiency often delay diagnosis, with non-autoimmune etiologies more likely in this age group. This report describes a rare case of autoimmune adrenalitis in an elderly patient. A 79-year-old male with type 2 diabetes, hypothyroidism, and hypertension underwent knee surgery and received intraoperative dexamethasone and postoperative opioids. During rehabilitation, he experienced lethargy, hypotension, altered mental status, and syncope. Initially, dehydration and opioid use were suspected. On a second Emergency room visit with similar symptoms, adrenal insufficiency was diagnosed and attributed to opioid-induced secondary adrenal insufficiency. Subsequent testing revealed high ACTH levels suggestive of primary adrenal insufficiency. However, negative autoimmune antibodies and the low likelihood of autoimmune adrenalitis made the diagnosis unclear. Treatment for adrenal insufficiency was initiated but later interrupted by the patient. Months later, during hip surgery, symptoms reappeared, and a seronegative autoimmune adrenalitis was diagnosed, supported by the patient’s history of autoimmune diseases. This case highlights the diagnostic challenges of autoimmune adrenalitis in elderly patients, where glucocorticoid and opioid use can obscure the etiology. It emphasizes the need to consider autoimmune adrenalitis even without confirmatory antibodies or typical presentation. Presentation: Sunday, July 13, 2025