Immunobullous diseases refer to a group of blistering skin condition with an autoimmune origin. The most common of these is pemphigus vulgaris and bullous pemphigoid. Depending on the type of skin condition, blisters or erosions may develop on the skin, eyes, or mucous membranes including the mouth. The chance of developing pemphigus vulgaris or bullous pemphigoid increases with age. Correct diagnosis requires skin biopsies. Typical treatment consists of oral immunosuppressive therapy including steroids. Further information on specific types of bullous skin eruptions are discussed below: Pemphigus vulgaris is a blistering disease that appears most commonly on mucosal surfaces such as the mouth, nose, eye, and genital area. The blisters of pemphigus are very shallow and rupture easily, therefore skin erosions rather than frank blisters are usually seen. Blisters most commonly begin in the mouth (approximately 60% of cases). Common areas of skin affected by pemphigus are the scalp, face, neck, armpits, and groin and lesions are often painful and can become easily infected. Pemphigus vulgaris is most common for individuals in their fifth to sixth decades of life. Affected individuals are susceptible to widespread infection and require treatment with immunosuppressives, often starting with oral steroids, to control the skin condition. Topical therapy is sometimes successful in cases of very limited skin involvement. Bullous pemphigoid (BP) is characterized by tense blisters on the skin. The mouth and other mucosal surfaces are typically not involved. Common areas of blisters are the trunk, thighs, and groin. The elderly are more commonly affected, although children, usually younger than 1 year old, are also a group that may be affected by bullous pemphigoid. The blisters of BP are deeper than pemphigus vulgaris. Early BP is sometimes confused with hives. Treatment usually begins with topical corticosteroids. Extensive skin involvement may require oral steroids or other antiinflammatory or immunosuppressive medications including tetracycline, niacinamide, dapsone, azathioprine, methotrexate or IVIG. Herpes gestationis, otherwise known as pemphigoid gestationis, is an autoimmune blistering disease that occurs in women during pregnancy. It is very rare, occurring in approximately 1 in 50,000 pregnancies and usually begins during the second trimester. Skin blisters usually begin around the belly button or extremities. Itching is often severe. This condition is closely related to bullous pemphigoid and is not related to the herpes virus. Herpes gestationis usually resolves after pregnancy but flares with birth control use or future pregnancies. Treatment requires steroids, topical for limited disease, and oral steroids for more significant skin involvement. Dermatitis herpetiformis (Duhring disease) is an extremely itchy, blistering disease closely related to gluten-sensitive enteropathy or celiac disease of the gut. The skin rash consists of red bumps that have been scratched. The condition usually appears on the scalp, buttocks, elbows, and backs of arms and legs. The skin condition flares with gluten intake (all grains except rice and corn). Diagnosis is confirmed by IgA staining in skin biopsy. Treatment typically consists of oral medications including dapsone or sulfapyridine.