Dermatology

Question 1

TBSA for SJS vs TEN?

Answer 1

SJS: <10%
TEN: >30%

Question 2

Bullous pemphigoid pathophysiology, presentation & management

Answer 2

• path: immunoglobulins & complement deposition in epidermal basement membrane –> blistering & bullae formation
• pres: prodrome of pruritic eczematous, papular or urticaria-like skin lesions –> tense bullae with intense pruritis (Nikolsky negative)
• mgmt: wound care, corticosteroids, doxycycline, immunosuppresants

Question 3

Pemphigus vulgaris pathophysiology, presentation & management

Answer 3

• path: IgG against keratinocytes in desmosomes causes acantholysis (loss of cell-to-cell adhesion)
• pres: flaccid bullae (+Nikolsky) with mucosal involvement (precedes skin)
• mgmt: steroids, immunomodulators (azathioprine, cyclophosphamide), doxycyline

Question 4

Infectious cause of SJS/TEN?

Answer 4

Mycoplasma pneumoniae (2nd most common cause after medications; particularly in children)