USMLE question

A 77-year-old man has multiple, painful blisters located on his face, neck, and torso. The patient complains that he cannot stop itching them. Which additional finding would suggest a diagnosis of Pemphigus Vulgaris rather than Bullous Pemphigoid?

A. Denuded skin and flaccid blisters
B. Fever and anorexia
C. Intact skin and tense blisters
D. Mouth Lesions
E. Posthealing hyperpigmentation

The answer turned out to be A. This is true because in pemphigus vulgaris, the autoimmune disorder where immunoglobulins (IgG) are produced against proteins called desmoglein. Targetted at the desmosomes at the epidermal layer, it creates a region of weakness allowing for the skin to be denuded (assuming what they meant was the Nikolsky's test).

However, is that the only answer? I respectfully disagree. I think D is also correct. Pemphigus vulgaris characteristically involves the mucous membranes (that includes the oral cavity) while bullous pemphigoid usually spares them.

Hottie99 posted:
"mouth ulcerations are associated with pemphigus vulgarius, and the oral mucosa is spared in bullous pemphigoid, that is another difference btw the 2 options, so therefore D can't be right, the question is describing pemphigus vulgaris, not bullous pemphigoid"

hottie99 didnt quite comprehend the question. utter bollocks about D can't be right

So in conclusion:
I believe both A and D may be right. but A is more right than D cos as high as 30% of people with bullous pemphigoid may have mouth lesions. so i guess NIKOLSKY WINS!