Section 6- Genetic and Bullous Diseases Flashcards
3 types of hereditary epidermolysis bullosa
Epidermolytic (EB simplex)
Junctional
Dermolytic
In Epidermolytic EB, cleavage and blister formation occurs in
Keratinocytes
In Junctional EB, cleavage and blister formation occurs in
Basal lamina
Lamina lucida of basement membrane
In Dermolytic EB, cleavage and blister formation occurs in
Most superficial papillary dermis
EB simplex gene mutations
Keratin 5 and 14
So called Koebner variant of EB simplex
Onset at birth to early infancy
Generalized blistering following trauma
Blisters tense or flaccid leading to erosions
Generalized EB simplex
Most common form of EB simplex
Localized
Gene mutations for junctional epidermolysis bullosa
Collagen XVII
Laminin
Blistering occurs below basal lamina
Healing accompanied by scarring and milia formation
Dystrophic EB
Gene mutation in dystrophic EB
Anchoring fibril VII collagen
Management for EB
Wound management
Nutritional support
Infection control
Flaccid blisters on skin and erosions on mucous membranes
No pruritus but burning and pain
Arising on NORMAL SKIN
Suprabasal acantholysis
More common in Jewish and Mediterranean
Usually starts in the oral mucosa
Pemphigus vulgaris
Term for loss of cell to cell adhesion in the epidermis
Acantholysis
Type of pemphigus:
Scaly and crusted lesions
Subcorneal acantholysis
Endemic in rural areas of Brazil
Pemphigus foliaceus
Transmembrane glycoprotein involved in pemphigus vulgaris
Desmoglein 3
Transmembrane glycoprotein involved in pemphigus foliaceus
Desmoglein 1
Sites of predilection of pemphigus vulgaris
Scalp Face Chest Axilla Groin Umbilicus
Drugs implicated in drug induced pemphigus vulgaris
Captopril
D-penicillamine
Type of pemphigus that has no mucosal lesions
Starts with scaly crusted lesions on an erythematous base
Pemphigus foliaceus
Site of predilection of pemphigus foliaceus
Face
Scalp
Upper chest
Abdomen
Localized variant of pemphigus foliaceus largely confined to seborrheic sites
Pemphigus erythematosus
Treatment for pemphigus
Prednisone 2-3mg/kg
Concomitant immunosuppressive agents:
Azathiorine, MTX, cyclophosphamide, mycophenolate mofetil, IVIG, rituximab
Most common bullous autoimmune disease
Bullous pemphigoid
Bullous autoimmune disease usually in the elderly
Pruritic papular and/or urticarial lesions with large tense bullae
Subepidermal blisters with eosinophils
Bullous pemphigoid
Sites of predilection of Bullous pemphigoid
Axilla
Medial thighs, groin, abdomen
Flexor forearm
Lower legs ( often first manifestation)
Management of Bullous pemphigoid
Systemic prednisone 50-100mg/day
Azathioprine
IVIG
Dapsone, MTX- milder cases
Pemphigoid gestationis occurs when in pregnancy?
4th-7th month
Chronic, recurrent, intensely pruritic
Sx precede lesions by 8-12h
Tiny vesicles, papules and urticarial plaques arranged in groups
Associated with gluten-sensitive enteropathy
Dermatitis herpetiformis
Patients with dermatitis herpetiformis have antibodies to this enzyme
Transglutaminases
Dermatitis herpetiformis patients have this deposits in the skin
IgA
Sites of predilection of dermatitis herpetiformis
Typical and almost diagnostic
Extensor areas- elbow knee
Strikingly symmetrical
Buttocks, scapular, sacral areas “butterfly fashion “
Management of dermatitis herpetiformis
Dapsone 100-150mg daily
Sulfapyridine 1-15g per day
Gluten free diet
Chronic subepidermal bullous disease associated with autoimmunity to type VII collagen
Epidermolysis bullosa acquisita
