<prompt> In congenital junctional epidermolysis bullosa , defect is seen in?Laminin 5Collagen type 7Collagen 4Collagen 3  <response>: EB comprises a group of genetically determined skin fragility disorders characterized by blistering of the skin and mucosae following mild mechanical trauma. Congenital epidermolysis bullosa of 3 types: 3 types Defect 1. Epidermolysis Bullosa Simplex 2. Epidermolysis Bullosa Junctional 3. Epidermolysis Bullosa Dystrophicans K5 14Q LamininQ Collagen-7Q Cogentinal is DIF Negative because no antibodies. Acquired epidermolysis bullosa: Ab against NCD non collagenous domain of Collagen 7 therefore DIF Positive 