There are a small number of researchers around the world who study blushing in order to understand it and help people who suffer erythrophobia. A really good book to go to in order to discover what is known currently is - Crozier, W. R., & de Jong, P. J. (Eds.). (2013). "The Psychological Significance of the Blush". Cambridge: Cambridge University Press. It will give a good overview on all the research by those researchers working in the field. In our university we are also working on research, with the current study (if you are interested) accessed via the Facebook page "Erythrophobia / érythrophobie".