It may be very difficult to differentiate between the many bullous skin diseases. Clinical presentation and age of onset can sometimes be helpful. Consultation with a dermatologist may facilitate diagnosis and treatment. More often, information from skin biopsy and immunofluorescent studies, such as DIF, IIF, or split-skin DIF or IIF, is required to make the diagnosis. It is hoped that current investigative studies will elucidate the role of immunoreactants found within the dermoepidermal basement membrane zone in the pathogenesis of these blistering diseases.