Summary

Vancomycin-induced thrombocytopenia is a rare side effect of a commonly used drug that may cause life-threatening disease. A 51-year-old man was treated for an episode of acute severe alcohol-induced pancreatitis complicated by development of a peripancreatic fluid collection. He developed fever of unknown origin and was treated with intravenous vancomycin and piperacillin with tazobactam. On day 6 of vancomycin therapy his platelet count dropped to 46×10⁹/L (237×10⁹/L on day 1 of treatment) and by day 8 of therapy platelets had fallen to a nadir of 9×10⁹/L. The patient at this stage displayed a florid purpuric rash and haematoma formation on attempted intravenous cannulation. A clinical diagnosis of vancomycin-induced thrombocytopaenia was made and the drug withdrawn. After 3 days a significant improvement in the platelet count was noted, rising to 56 × 10⁹/L. Immunofluorescence testing (PIFT) ruled out teicoplanin and heparin as causes of drug-induced thrombocytopenia.