It hasn't been studied in dogs less then 8 lbs OR less than 1 year of age. It has not been studied for use for more than 28 days, and is not intended for long term use. It is a steroid, and I suspect that if it is licked, then the dog is getting a dose of that orally. It can decrease some blood counts (leukocytes, lymphocytes, eosinophils), which is general immune suppression from steroids. It should not be used if there is any infection in the body or skin.
All that was found on the last page here: http://www.virbacvet.com/images/resources/detailers/Genesis_Detailer.pdf
All that was found on the last page here: http://www.virbacvet.com/images/resources/detailers/Genesis_Detailer.pdf