<prompt> A 85-year-old female developed multiple blisters on trunk and thigh. Nikolskys sign negative. The lesions came on and off. The most probable diagnosis is:Pemphigus vulgarisBullous pemphigoidLichen planusLepra reaction  <response>: Elderly patient, -ve nikolsky sign and multiple blisters on trunk and thigh point towards BP Other features BP AI subepidermal blistering disease. MHC II - HLA-DQ10301 is prevalent. Oral mucosal lesions are found rarely 10-40 Pruritus - Nontraumatized blisters heal without scarring Tense blisters--rupture-- flaccid lesions erosions- surmounting crust Rx: Mainstay- systemic glucocoicoids -Prednisone, 40 to 60 mgd.good response Azathioprine 1-2 mgkgday, Mycophenolate mofetil 20-35mgkgday, or Cyclophosphamide 1-2 mgkgday 