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.
Symblepharons are fibrous strands connecting the conjunctiva of the lid to the globe. Besides, reduced tearing with erosion and neovascularization of the cornea leads to corneal opacification and perforation. Scarring of the lid results in entropion (inward turning of the lid) and trichiasis (in-turning of the eyelashes). These conditions ultimately lead to blindness in approximately 20% of cases. It is crucial to go for follow-up because relapse occurs in 22% of those who were in remission and not undergoing therapy. Other mucous membranes
Less common sites that might get involved are nasopharynx, esophagus, and urethra. Nasopharyngeal involvement can lead to ulcerations of the septum and airway obstruction which might require tracheostomy. Esophageal disease may present with ulcerations, dysphagia, odynophagia, and stenosis. Stenosis at urethra, vaginal orifice and rectal have also resulted from chronic inflammation and scarring. Skin disease
About 25% of patients have cutaneous lesions, with tense vesicles or bullae, mainly on the face, neck, and scalp. Healing of erosion is either with or without atrophic scars. Cutaneous lesions of mucous membrane pemphigoid presents in 2 subtypes: (1)presents as generalized eruption of tense bullae without scarring (2) presents as localised blisters on an erythematous base, resulting in atrophic scarring. Mucous membrane pemphigoid is also associated with malignancy
Malignancy — MMP with antibodies directed against laminin 332 (previously known as laminin 5 and epiligrin) has been associated with an increased risk for internal malignancy.