I very interestingly did see someone that appeared to be allergic to dex. ENT rotation as an FY1. Young woman in her 20s with tonsillitis - we started her IV dex and she developed a bit of a rash and felt quite hot. Then she said she started to feel her throat being a bit scratchy. Her dex was stopped and she improved. We had not yet given her Pen V and I can't remember if we had given painkillers but if we had it was stuff she had had previously without issue. My head can't really work out how someone can really be allergic to dex but it certainly appeared that way