PP I have just been doing some research on the Dept Heath immunisation website, and it looks like it could be a mild reaction to the MMR vaccine, specifically the measles. Has she had a cough, runny nose or inflammation of her eyes? If it is from the vaccine, it is nowhere near as severe as she would have gotten it if she hadn't been vaccinated. If it is not a reaction to the vaccine then I would be asking the Dr about thrush. Em was not liking being cleaned at all while she had the thrush but now she is fine, and it persisted for a few weeks.