Mucosa is never involved in which of the following disorders –: (A) Dermatitis herpetiformis, (B) Pemphigus vulgaris, (C) Epidermolysis bullosa acquisita, (D) Toxic epidermal necrolysis
Answer is A. Mucosal involvement

Common                →   Pemphigus
Rare                      →   Pemphigoid
Not involved          →   Dermatitis herpetifo