Differential diagnosis of erythema multiforme major

Differential diagnosis of erythema multiforme major 
-graft versus host disease
-herpes gestationis
-staphylococcal scalded skin syndrome 
-epidermolysis bullosa 
-prophyria cutanea tarda 
-pemphigus foliaceus 
-linear IgA dermatosis 
-paraneoplasic pemphigus 
-cicatricial pemphigoid 
-dermatitis herpetiformis 
-contact dermatitis 
-bullous impetigo 
-drug eruption 
-bullous pemphigoid 
-pemphigus