DefinitionBullous pemphigoid is a skin disorder characterized by large blisters.Causes, incidence, and risk factorsThe cause is not known, but may be related to immune system disorders.Bullous pemphigoid usually occurs in elderly persons and is rare in young people. Symptoms come and go. In most patients, the condition goes away within 6 years.SymptomsSome people may have no symptoms, others may have mild redness and irration.In severe cases, they are multiple blisters, called bullae. The blisters are usually located on the arms, legs, or middle of the body. About one-third of persons with bullous pemphigoid also develop blisters in the mouth. The blisters may break open and form ulcers or open sores.Other symptoms may include:ItchingRashesMouth soresBleeding gumsSigns and testsTests that