Snapshot A 75-year-old woman living in a nursing home presents with a 1-month history of severe pruritus. She reports having unrelenting pruritis with a pink rash over her trunk and extremities. Though she tried multiple lotions, the pruritus does not improve. Approximately 2 days ago, she also noticed some blisters on her body. She has never had rashes like this before. On physical exam, she has several 1-3 cm tense bullae on her abdomen and upper arms. Nikolsky sign is negative. A skin biopsy is taken and sent for immunofluorescence. Introduction Clinical definition bullous pemphigoid (BP) is an autoimmune blistering disorder characterized by bullae (> 1 cm large, fluid-containing blister) and severe pruritus Epidemiology demographics more common in those > 70 years of age Pathogenesis auto-antibodies (IgG) against hemidesmosomes in the epidermal-dermal junction antibodies are below the epidermis main autoantigens are BP180 and BP230 this activates complement and inflammatory reaction which cause epidermal-dermal splitting Associated conditions drug use loop diuretics metformin neuroleptics neurologic conditions multiple sclerosis dementia Parkinson disease Prognosis can resolve spontaneously often recurs Presentation Symptoms severe pruritus may have history of eczematous or urticarial lesions before bullae formation Physical exam tense bullae with clear exudate may be hemorrhagic typically symmetrically distributed on trunks and extremities spares mucous membranes negative Nikolsky sign cannot cause separation, blister formation, or blister extension with blunt pressure or lateral traction (dragging finger on skin) may have vesicles Studies Labs autoantibodies in serum detected with enzyme-linked immunosorbent assay (ELISA) for monitoring disease activity anti-BP180 antibodies anti-BP230 antibodies Histology subepidermal blister with eosinophils direct immunofluorescence linear pattern of IgG and C3 deposition along the epidermal-dermal junction Differential Pemphigus vulgaris more severe than BP affects mucous membranes positive Nikolsky sign Treatment Conservative discontinue new medications indications if BP is suspected to be a drug reaction wound care indications all patients antiseptic care for erosions Medical topical corticosteroids indications first-line treatment often used with systemic treatments drugs clobetasol prednisone indications for widespread disease or if topical steroids are not feasible steroid-sparing immunosuppressant indications for those contraindicated to steroids drugs azathioprine Complications Skin and soft tissue bacterial infection of open lesions