Bullous pemphigoid vs Pemphigus vulgaris
How to tell Bullous pemphigoid and Pemphigus vulgaris apart when a board question makes them look alike.
Pemphigoid is tense subepidermal hemidesmosome disease; pemphigus is flaccid mucosal anti-desmoglein intraepidermal disease.
Side by side
Bullous pemphigoid causes tense bullae in older adults, usually without mucosal erosions, from IgG against hemidesmosomes at basement membrane.
Pemphigus vulgaris causes flaccid bullae and painful mucosal erosions from IgG against desmogleins with suprabasal acantholysis.
Autoantibodies disrupt dermal-epidermal anchoring, creating subepidermal blisters.
Autoantibodies disrupt keratinocyte desmosomes, creating intraepidermal acantholytic blisters.
Linear IgG/C3 along basement membrane and tense blisters support bullous pemphigoid.
Fishnet intercellular IgG, positive Nikolsky, and oral erosions support pemphigus vulgaris.
The trap
Both blister, but blister tension, mucosa, split level, and immunofluorescence separate them.
Watch it explained
Test it nowThe repair move
For autoimmune blistering, match tense versus flaccid to basement membrane versus desmosome target.
Try a free question
CoreA 76-year-old woman has 8 weeks of pruritic tense bullae on the trunk and groin on an urticarial erythematous base. There is no oral involvement. Nikolsky sign is negative. Skin biopsy shows a subepidermal blister with eosinophils. DIF shows linear IgG and C3 along the basement membrane. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Bullous pemphigoid. Bullous pemphigoid features tense subepidermal bullae in elderly patients, lacks mucosal involvement, negative Nikolsky, anti-BP180/BP230 antibodies, and linear IgG/C3 at the basement membrane on DIF.
Why the other choices are tempting
- B. Pemphigus vulgaris has flaccid INTRAepidermal bullae with prominent mucosal involvement and positive Nikolsky.
- C. Dermatitis herpetiformis has small grouped pruritic vesicles with granular IgA in dermal papillae.
- D. Epidermolysis bullosa acquisita has tense bullae but DIF shows IgG below the lamina densa with anti-collagen VII antibodies.
- E. Linear IgA bullous dermatosis has linear IgA (not IgG) at the basement membrane.
Flashcards
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What target supports bullous pemphigoid?
Hemidesmosome or basement membrane antibodies support bullous pemphigoid.
What target supports pemphigus vulgaris?
Desmoglein antibodies support pemphigus vulgaris.
Quick answers
What is the fastest way to tell Bullous pemphigoid from Pemphigus vulgaris?
Pemphigoid is tense subepidermal hemidesmosome disease; pemphigus is flaccid mucosal anti-desmoglein intraepidermal disease.
What is the key clue for Bullous pemphigoid?
Bullous pemphigoid causes tense bullae in older adults, usually without mucosal erosions, from IgG against hemidesmosomes at basement membrane.
What is the key clue for Pemphigus vulgaris?
Pemphigus vulgaris causes flaccid bullae and painful mucosal erosions from IgG against desmogleins with suprabasal acantholysis.
What is the common trap with Bullous pemphigoid vs Pemphigus vulgaris?
Both blister, but blister tension, mucosa, split level, and immunofluorescence separate them.