I absolutely do believe skin troubles reflect what's going on inside! Yeast is a sign of problems in the digestive system, something I am qualified to discuss as a long time industrial strength colon cleanser!!!
It took four years of intensive cleansing to remove the gunk someone had stapled (velcroed?) to the walls of my poor abused colon! Having achieved my main goal and turned 50 with a clean pink colon... and also having flushed my liver/gallbladder of a BUNCH of large stones... my skin has been perfect for the past two years. It is like a miracle (except that I was present for all the hard work it took to get there)!
I highly recommend the excellent textbook, Renew Your Life, Improved Digestion and Detoxification, http://www.renewyourlife.com
for an extensive discussion of our digestive system and troubles that can lie within, not least of all yeast!
And be aware: If our colon is not in wonderful condition... yeast can set up shop in the colon. Its long roots can punch holes in the walls of the colon through which much larger particles than should be passing into the blood can pass! (This is known as Leaky Bowel). This allows things like yeast itself, parasites and other trash to pass into the blood system, thence to the liver... and from there can travel anywhere the blood flows within the body. I have experienced yeast in the brain (brain fog, lethargy and headachiness are symptoms) and have done battle with the yeast beast!
The book gives a rundown of the procedure you must undertake to rid your system of yeast, and reestablish proper digestion.
Probiotics and so on are a good step, but only part of the picture.
If your skin is a problem DO look into flushing your liver! It took me 5-6 flushes at 2 week intervals before I passed The Mother Lode, 30-40 beautiful jade green stones the size of small prunes! Since that flush my skin has been perfect.