History:

 A 75-year-old man presented with itchy bullous eruption of two weeks duration. The bullae were tense containing clear fluid and arose from normal skin and some from red plaques. The rash involved mainly the extremities and less on trunk but no mucous membrane involvement. An intact blister was taken for histopathological examination showed subepidermal bulla contained and surrounded by mixed inflammatory infiltrate with many eosinophils within the blister. The condition was well controlled within one month on 30 mg oral prednisolone per day with gradual tapering to 10 mg per day as maintenance.