Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

OVERVIEW

• = immune complex mediated hypersensitivity -> severe erythema multiforme.
• separation of the epidermis from the dermis
• most authors believe toxic epidermal necrolysis (TEN) and SJS are different ends of the same spectrum of disease
• erythema multiforme major is considered a distinct disorder
• serious systemic disorder (multisystem)
• mortality proportional to BSA

Disease nomenclature is based on the extent of the skin lesions

• < 10% BSA = SJS
• 10-30% BSA = SJS/ TEN overlap syndrome
• > 30%= TEN

CAUSES (MIDI)

• malignancy related (carcinomas and lymphomas)
• infectious (viral, bacterial, fungal, protozoal)
• drug induced (penicillins, sulfa drugs, quinolones, cephalosporins, anticonvulsants, COX-2, immunosuppressants, allopurinol, corticosteroids)
• idiopathic

HISTORY

• prodrome: systemic symptoms (1-14 days)
• co-morbidities: HIV and SLE
• painful and burning rash with mucosal involvement

EXAMINATION

• mucocutaneous lesions: papules/vesicles -> clusters, nonpruritic involving all mucous membranes (oropharynx, airway, urethra, cornea) -> rupture leaving denuded skin
• can be target lesions
• %BSA involved
• fluid status
• nutritional status

INVESTIGATIONS

• standard investigations involved in resuscitation
• skin biopsy: subepidermal bullae, epidermal necrosis, perivascular lymphocytic infiltration
• skin and blood cultures
• bronchoscopy – airway involvement
• endoscopy – GI involvement

MANAGEMENT

• determined by the severity of the syndrome

Resuscitate

• A – may need to be intubated c/o mucosal involvement
• B – protective lung ventilation (can develop pulmonary complications: secretions, sloughing of bronchial epithelim, BOOP)
• C – fluid resuscitation similar to burn patient, large volumes proportional to BSA involved, will have a hyperdynamic circulation with vasodilatory shock (managed with careful fluids and inotropic support), monitor end-organ function -> urine output >1mL/kg/hr
• D – multimodal analgesia required -> may have to intubated and ventilated for analgesia
• E – keep warm and isolated if possible to decrease risk of superinfection, humified environment, warm OT

Specific treatment

• stop offending agent
• identify and treat underlying disease and secondary infection (antibiotics)
• burns dressings
• antibiotics for documented invasive superinfection
• avoid antibiotics that may exacerbate conditions (silver sulphadizine -> sulpha based)
• IgG and steroids – controversial (EuroSCAR study)
• consider plasma exchange

General treatment

• careful management of fluid-balance and electrolyte abnormalities required
• nutrition
• thromboprophylaxis

Disposition

• management in a burns unit if large TBSA involvement
• keep family informed
• consult dermatology and plastic surgery early and involve burns nurse

References and Links

• Eponymictionary – Stevens-Johnson Syndrome
• Albert Mason Stevens (1884-1945)
• Frank Chambliss Johnson (1894-1934)
• Alan Lyell (1917-2007)