Bullous pemphigoidhttps://en.wikipedia.org/wiki/Bullous_pemphigoid
Bullous pemphigoid refers all kinds of skin disorders that induce bullaes. "Bullous pemphigoid" is an autoimmune pruritic skin disease preferentially in older people, aged over 60. The formation of blisters in the space between the epidermal and dermal skin layers is observed in bullous pemphigoid.

  • A photo showing legs covered in popped blisters, which can affect the entire body.
  • Pemphgoid vulgaris is more common in older people.
  • The initial symptoms are sometimes in the form of hives.
References Mechanisms of Disease: Pemphigus and Bullous Pemphigoid 26907530 
Pemphigus and bullous pemphigoid are autoantibody-mediated blistering skin diseases. In pemphigus, keratinocytes in epidermis and mucous membranes lose cell-cell adhesion, and in pemphigoid, the basal keratinocytes lose adhesion to the basement membrane. Pemphigus lesions are mediated directly by the autoantibodies, whereas the autoantibodies in pemphigoid fix complement and mediate inflammation. In both diseases, the autoantigens have been cloned and characterized; pemphigus antigens are desmogleins (cell adhesion molecules in desmosomes), and pemphigoid antigens are found in hemidesmosomes (which mediate adhesion to the basement membrane).
 Bullous pemphigoid 31090818 
Bullous pemphigoid is the most frequent autoimmune bullous disease and mainly affects elderly individuals. Increase in incidence rates in the past decades has been attributed to population aging, drug-induced cases and improvement in the diagnosis of the nonbullous presentations of the disease. A dysregulated T cell immune response and synthesis of IgG and IgE autoantibodies against hemidesmosomal proteins (BP180 and BP230) lead to neutrophil chemotaxis and degradation of the basement membrane zone. Bullous pemphigoid classically manifests with tense blisters over urticarial plaques on the trunk and extremities accompanied by intense pruritus. Mucosal involvement is rarely reported. High potency topical steroids and systemic steroids are the current mainstay of therapy. Recent randomized controlled studies have demonstrated the benefit and safety of adjuvant treatment with doxycycline, dapsone and immunosuppressants aiming a reduction in the cumulative steroid dose and mortality.