Direct immunofluorescence(DIF) is negative in:
All of the above are autoimmune disorders except Epidermolysis Bullosa Dystrophica which is because of defective collagen.7 in dermis and hence DIF is negative.
Bullous Pemphigoid
Cicatricial pemphigoid
Epidermolysis Bullosa Dystrophica
Pemphigus Folaceous