Depending on how long you have been doing this diet your body could be flushing out all the toxins from your previous diet. It is part of the cleansing process. I have a friend who has recently done the whole30 and during the initial stages he broke out like crazy but it slowly stopped and the skin is looking better.
"If man made it, don't eat it" - Jack Lallane
People say I am on a "crazy" diet. What is so crazy about eating veggies, fruits, seafood and organ meats? Just because I don't eat whole wheat and processed food doesn't make my diet "crazy". Maybe everyone else with a SAD are the "crazy" ones for putting that junk in their system.