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, but, 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 aged over 70 years than it is in younger people. Classification IgG The forms of pemphigoid are considered to be connective tissue autoimmune skin diseases. There are several types: Gestational pemphigoid (PG) (formerly called Herpes gestationis) Bullous pemphigoid (BP) Rarely affects the mouth Mucous membrane pemphigoid (MMP) or (cicatricial pemphigoid), (No skin involvement) 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. IgA 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 Bullous pemphigoid 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. Presentation Primary lesions of small and large blisters, known as vesicles and bullae, are found on the skin and sometimes on the mucous membranes. Non-bullous pemphigoid In some patients, pemphigoid starts off with cutaneous manifestations of BP without bullae, as the only sign of the disease. Pruritic eczematous, papular, or urticaria-like skin lesions may also persist for weeks to months. Bullous phase The bullous stage of BP shows vesicles and bulla, appearing on apparently normal or erythematous skin, predominantly at the flexural aspects of the extremities and the lower trunk. Mucosal lesions, which typically are erosions of the oral mucosa, are present in 10 to 30 percent of patients. Occasionally, the blister fluid becomes blood-tinged. The blisters are tense, about 1–4 cm in diameter, leaving eroded and crusted areas, together with urticarial and infiltrated papules and plaques in an annular or figurate pattern. Homology between bullous pemphigoid antigens in the skin and neuronal antigens in the central nervous system has been proposed as a cause for