We report the case of a 35-year-old patient who presented with acute adrenal insufficiency, then developed fever, hypoalbuminuria, anasarca, thrombocytopaenia and anaemia. Lymphadenopathy appeared later with microscopic features typical of Castleman's disease. Clinical remission followed treatment with intravenous immunoglobulin. Circulating interleukin-6 levels were elevated initially but were normal after immunoglobulin therapy. We surmise that high circulating levels of interleukin-6 (and ACTH) may have induced haemorrhagic necrosis of the adrenal glands and accounted for the constitutional symptoms.