Summary

Cyanosis is an ominous physical sign indicating significant cardiac or respiratory disease. However, bluish discolouration mimicking cyanosis could occur in methaemoglobinaemia. The clinical implications being very different, it is important that the aetiology of bluish discolouration of tissues is correctly identified. A case is reported where the antianginal agent nicorandil was identified as the most likely cause for methaemoglobinaemia.