Is the management of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) based on the extent of the affected surface area or the degree of epidermal detachment?

Management of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Based on Epidermal Detachment

The management of Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) is based on the extent of epidermal detachment rather than the affected surface area, as this figure has greater prognostic value. 1

Classification Based on Epidermal Detachment

• SJS is defined as epidermal detachment of <10% body surface area (BSA) plus widespread purpuric macules or flat atypical targets 1
• Overlap SJS-TEN is defined as detachment of 10-30% BSA plus widespread purpuric macules or flat atypical targets 1
• TEN is defined as detachment of >30% BSA with or without widespread purpuric macules or target lesions 1

Clinical Assessment of Epidermal Detachment

• When assessing patients with suspected SJS/TEN, both the extent of erythema AND the extent of epidermal detachment should be recorded separately on a body map 1
• Epidermal detachment includes both:
  • Already detached epidermis (visible erosions and blisters) 1
  • Detachable epidermis (areas with positive Nikolsky sign) 1
• The Nikolsky sign is demonstrated when gentle lateral pressure causes lesional, detachable epidermis to slide over the dermis 1

Prognostic Significance

• The percentage of epidermal detachment is used in the SCORTEN scoring system to predict mortality 1
• Mortality rates increase significantly with greater epidermal detachment:
  • SJS: 1-5% mortality 2, 3
  • TEN: 25-35% mortality 2, 3

Management Implications Based on Detachment

• Patients with >10% BSA epidermal detachment should be admitted without delay to a burn center or ICU with experience in treating SJS/TEN 1
• The approach to wound management differs based on the extent of epidermal detachment:
  • Conservative approach: For limited detachment 1
  • Surgical approach: May be considered for detachment >30% BSA with clinical deterioration 1

Documentation and Monitoring

• Use the Lund and Browder chart to estimate the percentage of BSA involved 1
• Document both erythema and epidermal detachment separately, as they represent different aspects of the disease 1
• Monitor for progression of detachment, as this indicates worsening disease 1

Common Pitfalls to Avoid

• Do not rely solely on the extent of erythema for classification or prognosis, as this can lead to underestimation of disease severity 1
• Do not confuse SJS/TEN with other blistering disorders such as erythema multiforme major, which has different clinical features and causes 1, 4
• Avoid delaying transfer to specialized care when epidermal detachment exceeds 10% BSA, as this increases mortality risk 1
• Remember that epidermal detachment may progress rapidly, requiring frequent reassessment 1, 5

Differential Diagnosis Considerations

• Staphylococcal scalded skin syndrome has a more superficial level of skin cleavage and can be differentiated on skin biopsy 1, 2
• Immunobullous disorders like pemphigus vulgaris and bullous pemphigoid require immunofluorescence studies for differentiation 4, 2