Please note: Rosacea 101 is a comprehensive, 373 page book, covering the conventional and alternative treatments for rosacea and covers basic rosacea 101 knowledge for rosacea newbies. It is a must have book for those who need in one book what they need to know about rosacea. Chapter 3, What Causes Rosacea? on page 13, covers this subject. In this chapter I discuss the five main theories of what causes rosacea. In Appendix D - Other Theories on the Cause of Rosacea on page 169 I list seven other theories on what causes rosacea.