A hunt for the source of sepsis.

A 42-year-old woman presented with a 2-day history of drowsiness, confusion, worsening headache, high fevers, urticarial rash, bilateral leg pains and urinary retention. Preceding this was a 1-month history of headache unresponsive to various analgesics for which her general practitioner started carbamazepine. Suspected central nervous system infection was investigated and treated with cefotaxime. A full septic screen, lumbar puncture and MRI of the spine were all inconclusive. After 3 days, the patient deteriorated and repeated blood tests-initially unremarkable-revealed neutropaenia and acutely deranged liver function. Connective tissue disorder was considered due to a negative septic screen and lack of response to antibiotics, but autoimmune screens failed to reveal a culprit. At this point, carbamazepine was suspected and stopped, after which the patient and her blood results recovered dramatically. This adds to previous reports of known reactions to carbamazepine and reinforces recommendations that patients should be made aware of potential complications of this drug. 2014 BMJ Publishing Group Ltd.