Meningococcal purpura fulminans and severe myocarditis with clinical meningitis but no meningeal inflammation: a case report

International audienceBackground: During fulminant meningococcal septicaemia, meningococci are often observed in the cerebrospinal fluid (CSF) although the patients have frequently no meningeal symptoms. Meningococcal meningitis, by contrast, usually features clinical meningeal signs and biochemical markers of inflammation with elevated white blood cell count (pleiocytosis) in the CSF. Cases of typical symptomatic meningitis without these biochemical features are uncommon in adults.Case presentation: A 21-year-old male presented with meningococcal purpura fulminans and disseminated intravascular coagulation (DIC) associated with multiple organ dysfunction syndrome requiring hospitalization in the Intensive Care Unit. Despite typical meningeal clinical signs, lumbar puncture showed no pleiocytosis, normal glycorachia and normal proteinorachia, whereas the lactate concentration in the CSF was high (5.8 mmol/L). CSF culture showed a high inoculum of serogroup C meningococci. On day 2, after initial improvement, a recurrence of hypotension led to the diagnosis of acute meningococcal myocarditis, which evolved favourably within a week. During the hospitalization, distal ischemic and necrotic lesions were observed, predominantly on the fingertips, which were treated with local and systemic vasodilators.Conclusions: We report a rare case of adult meningococcal disease characterized by an intermediate form of meningitis between purulent meningitis and meningeal inoculation from fulminant meningococcal septicaemia, without classical signs of biological inflammation. It highlights the diagnostic value of CSF lactate, which may warrant administration of a meningeal dosing regimen of beta-lactam antibiotics. This case also demonstrates the potential severity of meningococcal myocarditis; we discuss its pathophysiology, which is distinct from other sepsis-related cardiomyopathies. Finally, the observed effects of vasodilators on the meningococcal skin ischemia in this case encourages future studies to assess their efficacy in DIC-associated necrosis