This prospective observational study investigated the relationship of the hypothalamic-pituitary-adrenal axis to inflammatory markers and to disease severity in children with meningococcal disease. In total, 32 children were studied: 10 with distinct meningococcal meningitis (MM), 10 with MM and septic shock, and 12 with fulminant meningococcal septicemia (FMS). Levels of adrenocorticotropic hormone (ACTH) and interleukin (IL)-6, IL-8, and IL-10 were lowest in the MM group and dramatically elevated in the FMS group. Cortisol and C-reactive protein levels were highest in the MM group and relatively low in the FMS group. Levels of ACTH and inflammatory markers decreased within the first 24 h of admission, but cortisol levels did not fluctuate. Cortisol was significantly inversely correlated with IL-6, IL-8, and IL-10 (P < or =.04). These results suggest that the adrenal reserve in children is insufficient to handle the extreme conditions and stress associated with severe meningococcal disease.