Isolated Adrenocorticotropic Hormone Deficiency Diagnosed After the Cessation of Glucocorticoid Therapy for Eosinophilic Esophagitis: A Case Report

Isolated adrenocorticotropic hormone deficiency (IAD) is a rare pituitary disorder that can cause adrenal insufficiency. However, due to its nonspecific symptoms, its diagnosis is often difficult and may be delayed. Patients with IAD require lifelong glucocorticoid (GC) replacement therapy. Contrastingly, GC-induced secondary adrenal insufficiency is a reversible condition that arises when patients receiving GC therapy reduce their GC dosage or discontinue therapy. Differentiating between IAD and GC-induced secondary adrenal insufficiency is clinically crucial. We report a unique case that required differentiation between these two conditions. A 71-year-old Japanese woman presented with symptoms of adrenal insufficiency after discontinuation of GC therapy for eosinophilic esophagitis. We conducted detailed interviews and repeated the endocrinological examinations. We concluded that her symptoms were owing to IAD rather than GC-induced secondary adrenal insufficiency. She began a lifelong hydrocortisone replacement therapy. This case suggests that when caring for patients undergoing GC therapy, it is important to consider the possibility of coexisting IAD and arrange endocrinological examinations if signs of adrenal insufficiency arise during the gradual reduction of GC treatment.