2. Definition
SJS/TEN:
Lesions: Small blisters on dusky purpuric macules or
atypical targets
Mucosal involvement common
Prodrome of fever and malaise common
Stevens-Johnson Syndrome:
Rare areas of confluence.
Detachment </= 10% BSA
Toxic Epidermal Necrolysis:
Confluent erythema is common.
Outer layer of epidermis separates easily from basal layer
with lateral pressure.
Large sheet of necrotic epidermis often present.
>30% BSA involved.
3.
4. Presentation
Fever (often >39) and flu-like illness 1-3 days
before mucocutaneous lesions appear
Confluent erythema
Facial edema or central facial involvement
Lesions are painful
Palpable purpura
Skin necrosis, blisters and/or epidermal detachment
Mucous membrane erosions/crusting, sore throat
Visual Impairment (secondary to ocular involvement)
Rash 1-3 weeks after exposure, or days after 2nd
exposure
5. Epidemiology
2-7/million people/year
SJS: age 25-47, TEN: age
46-63
Women: >60%
Poor prognosis:
Intestinal/Pulmonary
involvement
Greater extent of
detachment
Older age
Mortality:
SJS: 5%
TEN: 30%
Risk Factors:
HIV infection
Genetic factors
Certain HLA types
“Slow acetylators”
Polymorphisms in IL4
receptor gene
Concomitant viral infections
Underlying immunologic
diseases
Physical factors
UV light, radiation therapy
Malignancy
Higher doses of known
offenders
6. Pathogenesis
Secondary to cytotoxicity and delayed hypersensitivity reaction
to the offending agent.
Antigen is either the implicated drug or a metabolite.
Histopathology:
Granulysin (cytolytic protein produced
by cytotoxic T cells and NK cells)
Expression of HLA-DR and
intracellular adhesion molecule
(ICAM)-1 by
Keratinocytes
CD4 cells (in dermis)
CD8 T cells (in epidermis)
Apoptosis of keratinocytes
facilitated by
TNF-alpha, perforin and granzyme
secretion
fas-ligand expression (cell death receptor)
Subepidermal split with cell-poor bullous.
Epidermis shows full thickness necrosis.
8. Differential Diagnosis for Vesicular or
Bullous Rash
Bullous
Pemphigoid
Often affects
the elderly
Dermatitis Herpetiformis
Associated with gluten intolerance
Cicatricial Pemphigoid
Mucosal involvement, sometimes cutaneous
Pemphigus
Affects middle-aged or elderly
9. Differential Diagnosis, cont.
Linear IgA Disease
Itchy, ring-shaped, no internal disease
Contact Dermatitis
Varicella/Zoster Virus
Herpes Simplex Virus
Hand-Foot-Mouth
Disease
(Enteroviruses)
11. Treatment
Early diagnosis - biopsy
Immediate discontinuation of offending agent
Supportive care – pay close attention to ocular
complications
IV hydration (e.g. Parkland formula)
Antihistamines
Analgesics
Local v. systemic corticosteroids
Think about nursing requirements!
Possible treatment in burn unit, wound care
IVIg?
13. Resources:
Cooper, et al. The Washington Manual of Medical
Therapeutics, 32nd Edition. 2007.
High, et al. Stevens-Johnson syndrome and toxic
epidermal necrolysis: Management, prognosis, and
long-term sequelae. Up To Date. 2009.
Kasper, et al. Harrison’s Principles of Internal
Medicine, 16th Edition. 2005.
Nirken, et al. Stevens-Johnson syndrome and toxic
epidermal necrolysis: Clinical manifestations,
pathogenesis, and diagnosis. Up To Date. 2009.