• C-reactive protein;
  • pyrexia;
  • neutropenia

Summary This study describes the experience of a clinical haematology unit in dealing with pyrexial episodes in 62 patients. Serum C-reactive protein levels were serially estimated and proved to be useful in following the course of the illness. No significant difference could be demonstrated in the C-reactive protein levels of those patients with bacteriologically proven illnesses, those in whom a clinically evident infection was present, and those with a ‘pyrexia of unknown origin’. However, those patients in whom disease activity was thought to be responsible for the pyrexia had significantly lower C-reactive protein levels compared with those patients who had a septicaemic illness.