Skin Disorders - Blistering Disorders

Question 1

Erythema Multiforme

Answer 1

• diffuse targetoid lesions, palms and soles
• Herpes Simplex, drug reaction (antibiotics in particular)
• Histology: vacuolization of basal layer with apoptosis (dead keratinocytes)
• Principles of Therapy: supportive care

Question 2

Steven’s Johnson Syndrome/Toxic epidermal necrolysis

Answer 2

• targetoid lesions, widespread blistering and involving mucous membranes
• trunk and face, hemorrhagic crusting of mucous membranes HOSPITALIZATION
• <10% Steven’s Johnson Syndrome
• > 30% Toxic Epidermal Necrolysis
• 10-30% SJS/TEN
• Principles of Therapy: eliminate cause supportive care in burn unit, needs careful fluid and electrolyte management and urinary catheterisation

Question 3

Dermatitis Herpetiformis

Answer 3

• pruritic groups of blisters extensor/dorsal surfaces
• associated with Celiac Disease
• Histology: papillary dermal neutrophils microabcesses, granular deposits of IgA near DE junction
• Principles of Therapy: eliminate gluten, Dapsone is highly effective

Question 4

Pamphigus Vulgaris

Answer 4

• flaccid blisters have “Nikolsky sign” - blisters expand with pressure, break easily
• diffuse distribution - often with oral erosions
• high mortality rate before corticosteroids
• Histology: intra-epidermal bulllous separation with acantholysis, intercellular IgG reacts with desmoglein - surrounds acantholytic cells producing a fish net pattern of immunofluorescently labeled antibody
• Principles of Therapy: corticosteroids, immunosuppressants, fluid and electrolyte management, and antimicrobial prophylaxis

Question 5

Bullous Pemphigoid

Answer 5

• tense blisters which lack Nikolsky sign
• extremities of elderly
• Histology: subepidermal bullae (blister cavity) with eosinophils, linear IgG against hemidesmosomes along basement membrane at DE junction
• Princiles of Therapy: corticosteroids, immunosuppressants