Pemphigus Vulgaris

Question 1

What is pemphigus vulgaris (PV)?

Answer 1

A chronic autoimmune blistering disorder characterized by intraepidermal blisters due to autoantibodies targeting desmosomal proteins.

Question 2

Which proteins are targeted in PV?

Answer 2

Desmoglein 1 and Desmoglein 3, which are components of desmosomes in the epidermis.

Question 3

What is the hallmark feature of PV?

Answer 3

Fragile blisters that easily rupture, leading to painful erosions on the skin and mucous membranes.

Question 4

Who is most commonly affected by PV?

Answer 4

Middle-aged and older adults, typically between 40–60 years of age.

Question 5

Is there a gender predilection for PV?

Answer 5

PV affects men and women equally.

Question 6

Which ethnic groups are at higher risk for PV?

Answer 6

Higher prevalence in individuals of Ashkenazi Jewish, Indian, and Middle Eastern descent.

Question 7

What causes pemphigus vulgaris?

Answer 7

Autoantibodies (IgG) bind to Desmoglein 1 and 3, leading to loss of keratinocyte adhesion (acantholysis) and formation of intraepidermal blisters.

Question 8

What type of hypersensitivity reaction is PV?

Answer 8

Type II hypersensitivity reaction.

Question 9

How does Desmoglein distribution influence lesion location?

Answer 9

Desmoglein 3: Predominantly in mucous membranes → mucosal lesions.

Desmoglein 1: Predominantly in skin → skin lesions.

Question 10

What are the primary clinical features of PV?

Answer 10

Fragile, flaccid blisters that rupture easily, leaving painful erosions.

Involves mucous membranes (oral cavity, pharynx) in most cases.

Skin lesions are often found on the scalp, face, chest, axillae, or groin.

Question 11

How does mucosal involvement typically present?

Answer 11

Painful erosions in the mouth, pharynx, or genital mucosa, often as the first sign of disease.

Question 12

What is Nikolsky’s sign in PV?

Answer 12

Gentle pressure on unaffected skin causes epidermal detachment, indicating fragile keratinocyte adhesion.

Question 13

What is the Asboe-Hansen sign?

Answer 13

Lateral extension of a blister when pressure is applied to its edge.

Question 14

How is PV diagnosed?

Answer 14

Clinical presentation: Flaccid blisters and mucosal involvement.

Skin biopsy: Shows intraepidermal blisters with acantholysis.

Direct immunofluorescence (DIF): IgG and C3 deposition in a “fishnet” pattern in the epidermis.

Serology: Detection of circulating anti-Desmoglein 1 and 3 antibodies by ELISA.

Question 15

What histological feature is characteristic of PV?

Answer 15

Acantholysis: Loss of keratinocyte adhesion within the epidermis.

Question 16

What is the primary treatment for PV?

Answer 16

Systemic corticosteroids (e.g., prednisone) to suppress inflammation and autoantibody production.

Question 17

What immunosuppressive agents are used as steroid-sparing therapies?

Answer 17

Azathioprine.

Mycophenolate mofetil.

Methotrexate.

Cyclophosphamide.

Question 18

What biologic therapy is approved for PV?

Answer 18

Rituximab, an anti-CD20 monoclonal antibody, is highly effective for refractory or severe PV.

Question 19

How is pain and secondary infection managed in PV?

Answer 19

Topical corticosteroids or anesthetics for oral lesions.

Antimicrobial agents to prevent or treat secondary infections.

Question 20

What factors can trigger or exacerbate PV?

Answer 20

Medications (e.g., penicillamine, captopril, NSAIDs).

Physical or emotional stress.

UV radiation.

Surgery or trauma.

Question 21

How does PV differ from bullous pemphigoid (BP)?

Answer 21

PV: Intraepidermal blisters, flaccid, easily ruptured, involves mucous membranes.

BP: Subepidermal blisters, tense, rarely involves mucous membranes.