Hope this helps! Pemphigus Foliaceus is what is known as an auto-immune skin disease. All cells in the body are "labelled" friend or foe depending on what they are. Bacteria for example are recognised as being "foe" and therefore targetted by the immune system and removed. In animals suffering from auto-immune disease (AI) either the labelling system can go wrong, or the immune system's method of reading the labelling can go wrong.
In PF, it is the skin or mucous membrane that are affected often causing vesicles, blisters, or blisters. Although very rare in dogs, it is manefested as an exfoliative scaling lesions.
There is no real cure, but it can be controlled by using immuno-suppressive drugs such as corticosteroids or azothioprine. Although this often works, there can be unpleasent side effects seen due to the high doses needed. Sometimes, it is only a temporary disease and may "sort itself out" during time.