Pemphigus vulgaris	Mucous membrane pemphigoid
Etiology Target proteins	– Autoimmune reaction – Intercellular keratinocyte protein (desmoglein 3) destroyed by auto antibodies	– Autoimmune reaction to basement membrane proteins: – Lamina 5 – BP 180
Clinical	Intraepithelial blisters	Subepithelial blisters
Site	– Oral mucosa – Skin – Mucosa	– Oral mucosa – Conjunctiva – Skin rarely
Histology	– Intraepithelial clefting – Loss of desmosomal contacts therefore free floating acantholytic Tzanck cells	– Subepithelial clefting – Chronic inflammatory infiltrate
Direct immunofluorescence testing	Circulating auto IgG	No circulating auto IgG

Pemphigus vulgaris

• Autoimmune blistering disorder
• Results in loss of integrity of intercellular attachments within epidermis and mucosal epithelium

Subtypes:

• P. Vulgaris (common)
• P. Vegetans (wart like)
• P. Foliaceus (flower like)
• P. Erythematosus (reddened)

Nikolsky’s sign: Positive – stroke mucosa gently, vesicle or bulla appears

Management: Corticosteroids + Azathioprine + Cyclophosphamide

Prognosis: Good. Fatal if untreated

Mucous membrane pemphigoid

• Autoimmune blistering disorder
• Results in loss of integrity of dermal-epidermal junctions
• Affects oral tissues in 30% of cases
• More severe

Management: Corticosteroids

Prognosis: Fair

Differential diagnosis:

• Erythematous lichen planus
• Linear IgA disease
• Discoid lupus erythematous
• Contact allergy