"Healing With Whole Foods," by paul pitchford is a book I highly recommend if you wish to maximize your health through diet. This 700 page reference book addresses health issues from the East/West perspective.
Diets, herbs, vitamins, minerals and more are outlined for specific imbalances as they apply to the varying constitutional types. Different diets are recommended for the same disease, depending on your constitutional type. Food combining is gone over at length, and I was quite surprised that some of my combinations were not ideal.
He addresses facial rash issues as falling under one of two types of imbalances: Yin Deficiency or Yang Excess in the system, (Eastern point of view, both manifesting as excess heat).
Rosacea has a lengthy and varied list of causes, as well as types. This book offers a broad, sane approach to rebuilding the system to genuine health, not just a quick fix.