IMMUNOLOGICALLY MEDIATED SKIN DISEASE Flashcards
Which of the following immunologically mediated blistering diseases is characterized by flaccid blisters, denuded skin, and oral mucosal lesions?
A) Bullous pemphigoid
B) Pemphigus vulgaris
C) Epidermolysis bullosa acquisita
D) Dermatitis herpetiformis
Correct Answer: B) Pemphigus vulgaris
Rationale: Pemphigus vulgaris presents with flaccid blisters and erosions involving both the skin and mucosal surfaces due to autoantibodies targeting desmoglein 3 (Dsg3) and, in some cases, desmoglein 1 (Dsg1).
Which histological feature is characteristic of bullous pemphigoid?
A) Acantholysis and suprabasal blister formation
B) Subepidermal blister with eosinophil-rich infiltrate
C) Subepidermal blister with neutrophil-rich infiltrate
D) Granular deposits of IgA in dermal papillae
Correct Answer: B) Subepidermal blister with eosinophil-rich infiltrate
Rationale: Bullous pemphigoid is characterized by subepidermal blister formation with eosinophil-rich infiltrate and linear IgG and/or C3 deposits along the basement membrane zone (BMZ).
Which blistering disorder is most associated with painful stomatitis and lichenoid eruptions?
A) Bullous pemphigoid
B) Linear IgA disease
C) Paraneoplastic pemphigus
D) Epidermolysis bullosa acquisita
Correct Answer: C) Paraneoplastic pemphigus
Rationale: Paraneoplastic pemphigus is often linked to underlying malignancies and presents with painful stomatitis, papulosquamous eruptions, and lichenoid features. The autoantigens involved include plakin family proteins and desmosomal cadherins.
Which autoantigen is targeted in dermatitis herpetiformis?
A) Desmoglein 1 (Dsg1)
B) BPAG2
C) Epidermal transglutaminase
D) Type VII collagen
Correct Answer: C) Epidermal transglutaminase
Rationale: Dermatitis herpetiformis is strongly associated with gluten-sensitive enteropathy (celiac disease) and is caused by IgA autoantibodies targeting epidermal transglutaminase.
Which clinical presentation is most characteristic of epidermolysis bullosa acquisita?
A) Flaccid blisters and oral erosions
B) Tense inflammatory blisters and widespread scarring
C) Pruritic papules and vesicles on extensor surfaces
D) Teardrop-shaped subepidermal blisters
Correct Answer: B) Tense inflammatory blisters and widespread scarring
Rationale: Epidermolysis bullosa acquisita presents with blisters, erosions, and scarring in sites prone to trauma, often resembling bullous pemphigoid but with involvement of type VII collagen.
Which autoantigen is implicated in bullous pemphigoid?
A) BPAG2
B) Desmoglein 1 (Dsg1)
C) Type VII collagen
D) Epidermal transglutaminase
Correct Answer: A) BPAG2
Rationale: Bullous pemphigoid is caused by autoantibodies against BPAG1 and BPAG2, leading to subepidermal blistering with linear IgG and/or C3 deposition at the BMZ.
