Pyrexia of unknown origin. Presenting sign of hypothalamic hypopituitarism.

A 62-year-old man was admitted to hospital 10 times over 12 years because of pyrexia of unknown origin. Hypothalamic hypopituitarism was diagnosed by dynamic tests including clomiphene, LRH, TRH and chlorpromazine stimulation. Lack of ACTH was demonstrated by long and short tetracosactrin tests. The aetiology of the disorder was believed to be previous encephalitis. Following substitution therapy with adrenal and gonadal steroids there were no further episodes of fever.