Vesiculobullous Dermatoses

DDX

• Bullous pemphigoid
• Pemphigus vulgaris
• Erythema multiforme
• Dermititis herpetiformis
• Linear IgA disease
• Herpes Gestationis
• Epidermolysis bullosa acquisita
• Paraneoplastic pemphigus

Bullous Pemphigoid

vs 

Epidermolysis Bullosa Aquisita

Both show Linear IgG and Complement C3 at DE junction

• EBA shows immunoflourescence at base only if split lesion with hypertonic saline
• Bullous pemphigoid shows immunoflourescence at roof only in 80% of cases (so could Linear IgA)

Bullous Pemphigoid 

Charactaristics

• Elderly patients
• Tense blisters on urticarial erythematous base
• 1/3 have oral lesions (less common than in pemphigus
• Linear IgG and C3 at DE junction on immunofl
• Indirect DF positive in 70%

Bullous Skin Dz

Linear Flourescence at DE Junction

• Bullous Pemphigoid
• Lupus
• Epidermolysis Bullous

Pemphigus Group

• Pemphigus Vulgaris
• Pemphigus foliaceus
• IgA pemphigus
• Drug-induced pemphigus
• Paraneoplastic pemphigus

Pemphigus Group

• Nikolsky sign (pressure on skin unroofs/extends) secondary to acatholysis (separation of epidermal cells/cells float apart)
• Ag is  glyco protien that combines with plakoglobulin that holds cells together
• Oral lesions much more common than with pemphigoid
• Blisters are more flacid

Acantholysis

disruption of the intercellular connections between keratinocytes of the epidermis, caused by lysis of intercellular cement substance

Drug-Induced Pemphigus

• Thiols ie Captopril, Piroxicam,gold
• Antibiotics ie Amoxicillin, ceftazidime, INH, PCN
• Pyrazolon dervatives ie aminopyrene,(antipyretic/pain reliever) oxyphenylbutazone (NSAID Tandearil)
• Misc:  barbitol, digoxin, propranalol, heroin

Pemphigus Vulgaris

"Flourescent chicken wire"

Ag is on the individual epidermal cells,

not at DE juction

Dermatitis Herpetiformis

• INTENSELY pruritic
• Grouped vesicles located symmetrically at elbows, knees, buttocks, scapula,scalp
• Histo:  neutrophils at tip of dermal papillae
• DIF:  IgA *  
• IgA activates the alternate not classical pathway of complement*

*UNIQUE to DH

IgA related Bullous Skin Diseases

• Dermatitis Herpetiformis-GRANULAR IgA at dermal papillae
• Herpes  Gestationis-IgA and Complement at DE junction

 Cutaneous Toxicities of drugs that result in 

Immune Bullous disorders

• Erythema multiforme spectrum from target lesions to TEN
• Toxic epidermal necrolyis
• Fixed drug eruptions

Pattterns of Immunoflourescence

in Bullous Skin Lesions

Intercellular deposition of antibody:

• Pemphigus group
• Paraneoplastic pemphigus

• Pemphigoid group
• Epidermolysis Bullousa Aquisita
• Bullous Lupus Erythematosis