[Clinical reasoning and decision making in practice. Fever, purpura and hemiparesis in a 29-year old female].

A 29-year-old female was admitted with fever, purpura and hemiparesis. She was treated for meningococcal sepsis after a Gram stain of a purpuric lesion showed Gram-negative diplococci. CT scan of the brain revealed multiple haemorrhagic lesions with obliteration of the sulci and basal cisterns. In the course of the disease she developed an acute myocardial infarction. Besides wall motion abnormalities, echocardiography revealed a bicuspid aortic valve with a vegetation on one of its cusps. Despite these findings, both the doctors who were involved in the treatment of this patient and the consulted physician in this article failed to reject the diagnosis 'meningococcal sepsis' and to replace it with a more likely diagnosis, namely Staphylococcus aureus endocarditis. The patient died one day after admission due to transtentorial herniation. Although purpuric lesions are common in meningococcal sepsis, they are not specific for this disease. The false-positive result of the Gram stain resulted in a process known as 'premature closure': the diagnosis of meningococcal sepsis was accepted before it was fully verified. In this case, the consequence was that other diagnostic tests and symptoms were misinterpreted with the result that inappropriate antibiotic therapy was instituted.