Too little or too much corticosteroid? Coexisting adrenal insufficiency and Cushing's syndrome from chronic, intermittent use of intranasal betamethasone

To report the puzzling, rare occurrence of coexisting adrenal insufficiency and Cushing's syndrome from chronic, intermittent use of intranasal betamethasone spray. A 62-year-old male was referred to our endocrinology clinic for management of adrenal insufficiency. This previously healthy individual began to experience chronic sinus symptoms in 2007, was treated with multiple ensuing sinus surgeries, and received oral glucocorticoid for 6 months. In the following 5 years, he suffered severe fatigue and was diagnosed with secondary adrenal insufficiency. He could not be weaned from corticosteroid and developed clear cushingoid features. In our clinic, careful inquiry on medications revealed chronic, intermittent use of high-dose intranasal betamethasone since 2008, which was not apparent to his other treating physicians. His cushingoid features significantly improved after holding intranasal betamethasone. LEARNING POINTS: Chronic, intermittent intranasal betamethasone can cause secondary adrenal insufficiency and iatrogenic Cushing's syndrome when used in excess. Topical corticosteroid use should be considered in the differential diagnosis of adrenal insufficiency or Cushing's syndrome.