Secondary adrenal insufficiency manifested as an acute febrile illness.

High fever occurred in a 30-year-old woman five weeks after transsphenoidal hypophysectomy for a pituitary adenoma. Extensive investigation failed to reveal any evidence of infection, and the clinical findings suggested the fever to be a manifestation of steroid withdrawal. Either suboptimal dosage of corticosteroid replacement therapy or omission of such therapy in adrenal insufficiency must be considered in the differential diagnosis of enigmatic postoperative fever.