Vesiculobullous Disease

Question 1

Bullous Pemphigoid

Answer 1

• type II hypersensitivity rxn (IgG) against the epidermal/dermal junction
• phemphigoiD = deeper blister
• can be induced by: drugs, physical triggers, other skin disorders, immunosuppressed status
• s/sxs: 1st sx = prodromal pruritus, eczematous or urticarial plaques followed by SCC in situ/Bowen’s Disease (has not invaded the dermis) tense, large bullae that do NOT rupture easily
• Negative Nikolsky sign
• most commonly appear in groin, axilla, trunk and flexural areas
• **no mucus membrane invovlement**
• diagnosis: skin biopsy with direct immunofluorescence
  
  • autoantibodies against BP antigen 230 & 180
• ​tx: high potency topical steroids or systemic corticosteroids if severe

Question 2

Bullous Pemphigus

Answer 2

aka pemphigus vulgaris

• **life threatening**
• **mucous membrane involvement** then painful, flaccid bullae that are ruptured easily
• positive Nikolsky sign
• diagnosis: punch biopsy = intraepithelial splitting with acantholysis
  
  • direct immunofluorescence: IgG throughout the epidermis and basal keratinocytes that look like a row of tombstones
• tx: Systemic tx: high-dose corticosteroids + local wound care = should treat like burns
  
  • can also do steroid sparing immunosuppressants = methotrexate, azathiaprine

Question 3

Dermatitis Herpetiformis

Answer 3

• strongly associated with celiac disease
• IgA immune complex deposition in the dermal papillae
• s/sxs: intensely itchy papulovesicular rash most common on the extensor surfaces (forearms, elbows, knees), buttocks, back and scalp
• • diagnosis: clinical + IgG antibodies for celiac disease
    
    • definitive diagnosis: direct immunofluorescence = Ig deposition within the papillary dermis
• tx: gluten free diet
  
  • dapsone = first line short-term management
    
    • SEs: hemolysis, methemoglobinemia and peripheral neuropathy