<prompt> A 40 year old male developed persistant oral ulcers followed by multiple flaccid bullae on trunk and extremities. Direct immunofluorescence examination of a skin biopsy showed intercellular IgG deposits in the epidermis. The most probable diagnosis is:Pemphigus vulgarisBullous PemphigoidBullous Lupus erythematosusEpidermolysis bullosa acquisita  <response>: It is an autoimmune intraepidermal blistering disease due to antibodies against desmoglein 3. It begins as painful oral erosions followed by flaccid blisters on the trunk, face, scalp. Ref: Current Literature Dermatology By Pasricha, Pages 197, 202; Rooks Textbook of Dermatology, 8th Edition. 