What’s the difference between bullous pemphigoid and pemphigus vulgaris?

What’s the difference between bullous pemphigoid and pemphigus vulgaris?

Both bullous pemphigoid and pemphigus vulgaris are autoimmune blistering diseases. Pemphigus vulgaris symptoms share some similarities to bullous pemphigoid symptoms. Pemphigus vulgaris almost always starts on the mucous membranes inside of your mouth. Very few people have involvement of the skin. Also, the blisters in pemphigus vulgaris are much more fragile than those in bullous pemphigoid.

People with pemphigus vulgaris usually have erosions if their skin is involved, not intact blisters like bullous pemphigoid people typically develop. If you have pemphigus vulgaris, the top layers of your skin easily separate from your lower layers of skin with pressure, usually from pressing or rubbing (Nikolsky sign).

While all people with bullous pemphigoid have skin involvement, only about 33% of them develop blisters in their mouth.