Pemphigoid is a group of rare autoimmune blistering diseases of the skin and mucous membranes. As its name indicates, pemphigoid is similar in general appearance to pemphigus, however unlike pemphigus, pemphigoid does not feature acantholysis, a loss of connections between skin cells.

Pemphigoid is more common than pemphigus and is slightly more common in women than in men. It is also more common in people older than 70 than it is in younger people.

The forms of pemphigoid are considered to be connective tissue autoimmune skin diseases. There are several types:

Bullous and mucous membrane pemphigoid usually affect persons who are over age 60. Gestational pemphigoid occurs during pregnancy, typically in the second or third trimester, or immediately following pregnancy.

Pemphigoid is usually considered to be mediated by IgG, but IgA-mediated forms have also been described.

IgA-mediated immunobullous diseases can often be difficult to treat even with usually effective medications such as rituximab.

Bullous pemphigoid (BP) is a rare and chronic autoimmune disorder characterised by large sub-epidermal blisters called bullae that predominantly involves the skin and less commonly the mucous membranes. It is the most common type of the pemphigoid group, representing 80% of sub-epidermal immunobullous cases. It is more commonly known as cutaneous pemphigoid.

Primary lesions of small and large blisters, known as vesicles and bullae, are found on the skin and sometimes on the mucous membranes.