What is the difference between Stevens Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN)?

From the Guidelines

Stevens Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are distinct conditions that differ primarily in the extent of skin detachment, with SJS involving less than 10% of body surface area and TEN affecting more than 30% of the body surface. The main difference between SJS and TEN lies in the severity of skin detachment, with SJS/TEN overlap syndrome occurring when 10-30% of the body surface is affected 1. Both conditions typically begin with flu-like symptoms followed by painful rash and blistering, with mucous membrane involvement in most cases. They share the same causes, primarily medications like allopurinol, aromatic anticonvulsants (carbamazepine, phenytoin, lamotrigine), sulfonamide antibiotics, and certain NSAIDs. The pathophysiology involves a T-cell mediated cytotoxic reaction and apoptosis of keratinocytes. Management for both conditions includes immediate discontinuation of the suspected medication, supportive care in a burn unit or ICU, fluid and electrolyte management, wound care, and prevention of complications 1. The mortality rate is higher in TEN (25-35%) compared to SJS (5-10%), and both conditions can lead to long-term complications including ocular, respiratory, and skin problems. Key considerations in management include early assessment and transfer to specialized care, particularly for high-risk patients, and the use of treatments such as intravenous immunoglobulin and systemic corticosteroids, although the evidence for these treatments is not definitive 1. Eye involvement is a significant concern, with acute ocular involvement occurring in up to 74% of patients, and chronic complications such as severe dry eyes and trichiasis being common 1. In children and young people, management should be tailored to the individual's needs, with consideration of the extent of skin loss, systemic involvement, and comorbidities, and the importance of early transfer to specialized care 1.

Key Points

• SJS and TEN differ in the extent of skin detachment
• Both conditions share common causes and pathophysiology
• Management includes supportive care, wound care, and prevention of complications
• Mortality rates are higher in TEN than SJS
• Long-term complications can include ocular, respiratory, and skin problems
• Early assessment and transfer to specialized care are critical, particularly for high-risk patients
• Eye involvement is a significant concern, with both acute and chronic complications possible
• Management in children and young people should be tailored to the individual's needs, with consideration of the extent of skin loss, systemic involvement, and comorbidities.

Management Considerations

• Immediate discontinuation of the suspected medication
• Supportive care in a burn unit or ICU
• Fluid and electrolyte management
• Wound care
• Prevention of complications
• Consideration of treatments such as intravenous immunoglobulin and systemic corticosteroids
• Early assessment and transfer to specialized care, particularly for high-risk patients
• Management of eye involvement, including acute and chronic complications.

Treatment Options

• Intravenous immunoglobulin
• Systemic corticosteroids
• Supportive care in a burn unit or ICU
• Fluid and electrolyte management
• Wound care
• Prevention of complications.

Note: The evidence provided is based on the studies cited, including 1.

From the Research

Difference between Stevens Johnson Syndrome and Toxic Epidermal Necrolysis

The main difference between Stevens Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN) is the extent of skin detachment:

• SJS is defined as skin involvement of < 10% 2, 3
• TEN is defined as skin involvement of > 30% 2, 3
• SJS/TEN overlap is defined as 10-30% skin involvement 2, 3

Clinical Characteristics

Both SJS and TEN are severe adverse cutaneous drug reactions that predominantly involve the skin and mucous membranes, characterized by:

• Mucocutaneous tenderness and typically hemorrhagic erosions, erythema and more or less severe epidermal detachment presenting as blisters and areas of denuded skin 3
• "Influenza-like" prodromal phase (malaise, fever), followed by painful cutaneous and mucous membrane (ocular, oral, and genital) lesions, and other systemic symptoms 2

Diagnosis and Treatment

Diagnosis relies mainly on clinical signs together with the histological analysis of a skin biopsy showing typical full-thickness epidermal necrolysis due to extensive keratinocyte apoptosis 3 Treatment options include:

• Systemic corticosteroids, which have shown a survival benefit for SJS/TEN patients 4
• Cyclosporine treatment, which has also shown promising results 4
• Supportive care, including wound management and prevention of complications such as infection and ocular scaring 5

Complications and Prognosis

Both SJS and TEN are life-threatening conditions with high mortality rates:

• The average reported mortality rate of SJS is 1-5%, and of TEN is 25-35% 3
• More than 50% of patients surviving TEN suffer from long-term sequelae of the disease 3
• Complications can include ocular, cutaneous, or renal involvement, as well as nasopharyngeal, esophageal, and genital mucosal involvement with blisters, erosions, and secondary development of strictures 2, 6