What is the significance of surface area in Stevens-Johnson Syndrome (SJS)?

From the Guidelines

Surface area involvement is a critical factor in Stevens-Johnson Syndrome (SJS) as it helps distinguish SJS from other more severe forms of the disease spectrum, with less than 10% of the body surface area affected by epidermal detachment indicating SJS, 10-30% indicating SJS/TEN overlap syndrome, and greater than 30% signifying Toxic Epidermal Necrolysis (TEN) 1.

Significance of Surface Area in SJS

The significance of surface area in SJS lies in its prognostic implications, as mortality rates increase with greater surface area involvement.

• The Rule of Nines or Lund-Browder charts are commonly used to calculate the affected body surface area.
• Surface area assessment guides treatment decisions, including:
  • Whether hospitalization is needed
  • If ICU-level care is required
  • The intensity of supportive measures necessary
• Patients with larger affected areas typically need more aggressive fluid management, wound care, and monitoring for complications like sepsis and electrolyte imbalances.

Clinical Phenotypes of SJS/TEN

The clinical phenotypes of SJS/TEN can be differentiated based on the extent of epidermal detachment:

• SJS: epidermal detachment less than 10% BSA plus widespread purple/red macules or flat atypical targets
• Overlap SJS-TEN: detachment or skin necrosis of 10–30% BSA plus widespread purpuric macules or flat atypical targets
• TEN: detachment or skin necrosis greater than 30% BSA

Management of SJS/TEN

The management of SJS/TEN involves:

• Discontinuation of any potential culprit drug causing SJS/TEN immediately
• Establishment of peripheral venous access and commencement of appropriate intravenous fluid resuscitation if clinically indicated
• Ascertainment of whether the patient can maintain adequate hydration and nutrition orally, and insertion of a nasogastric tube and institution of nasogastric feeding if necessary
• Insertion of a urinary catheter when urogenital involvement is indicated
• Use of an appropriate dressing on exposed dermis to reduce fluid and protein loss, limit microbial colonization, and help pain control
• Consideration of a surgical approach involving debridement of detached epidermis and physiological wound closure using biosynthetic xenograft or allograft in cases of failure of conservative management

Conclusion is not allowed, so the answer will continue without one.

It is essential to note that the extent of epidermal detachment, rather than the amount of erythema, has prognostic value 1. The British Association of Dermatologists' guidelines for the management of SJS/TEN in adults recommend that patients with large areas of epidermal loss (> 10% BSA) are admitted to a specialist intensive care unit (ICU) for critical care management and specialist nursing 1. Early and accurate assessment of involved surface area is essential for appropriate triage and management of these potentially life-threatening conditions. The most recent and highest quality study, published in 2019, provides guidance on the management of SJS/TEN in children and young people, emphasizing the importance of surface area assessment in guiding treatment decisions 1.

From the Research

Significance of Surface Area in Stevens-Johnson Syndrome

The surface area affected by Stevens-Johnson Syndrome (SJS) is a critical factor in determining the severity of the condition.

• The severity of SJS is often classified based on the percentage of body surface area (BSA) affected, with SJS typically involving less than 10% BSA and toxic epidermal necrolysis (TEN) involving more than 30% BSA 2, 3.
• A study found that patients with SJS/TEN presented with an average of 60% of the body surface area affected and 31% of epidermal sloughing 2.
• The extent of the affected body surface area is a key factor in determining the treatment approach, with patients having a larger affected area requiring more intensive care and supportive measures 2, 3.
• The surface area affected can also impact the risk of complications, such as hypoproteinemia and secondary infections, which are more common in patients with TEN than in those with SJS 3.

Clinical Implications

The surface area affected by SJS/TEN has significant clinical implications, including:

• The need for rapid admission to a critical care area with experience in the care of burn patients for patients with a large affected surface area 2.
• The use of supportive care measures, such as wound care and fluid management, which are critical in managing patients with SJS/TEN 4.
• The potential use of adjuvant therapies, such as intravenous immunoglobulin (IVIG) or cyclosporine, which may be considered in patients with a large affected surface area or severe disease 5, 6.
• The importance of monitoring for complications and adjusting treatment accordingly, based on the extent of the affected surface area and the patient's overall clinical condition 3, 6.