Severity-of-Illness Score for Toxic Epidermal Necrolysis (SCORTEN)
The Severity-of-Illness Score for Toxic Epidermal Necrolysis (SCORTEN) is a prognostic tool used in patients with Stevens-Johnson syndrome (SJS), toxic epidermal necrolysis (TEN), and SJS/TEN overlap. It is designed to estimate mortality risk early in the course of illness using a small set of objective clinical and laboratory findings. Because SJS/TEN can deteriorate quickly, early risk stratification helps clinicians align level of monitoring, supportive care intensity, and multidisciplinary coordination.
What SCORTEN measures
SCORTEN assigns 1 point for each positive criterion present at initial assessment. The total score ranges from 0 to 7. Higher scores correspond to higher predicted mortality risk.
SCORTEN criteria (1 point each)
- Age > 40 years
- Presence of active malignancy
- Heart rate > 120 beats/min
- Initial epidermal detachment > 10% body surface area (BSA)
- Serum urea (BUN) > 28 mg/dL
- Serum glucose > 252 mg/dL
- Serum bicarbonate < 20 mEq/L
How to calculate
- Assess each of the seven criteria at presentation.
- Add 1 point for each criterion met.
- Map the total to the corresponding mortality band.
- Use the result alongside dynamic bedside assessment and trajectory.
Mortality interpretation by total score
- 0-1 points: approximately 3.2% predicted mortality
- 2 points: approximately 12.1% predicted mortality
- 3 points: approximately 35.3% predicted mortality
- 4 points: approximately 58.3% predicted mortality
- >=5 points: >90% predicted mortality
Clinical context and bedside application
SCORTEN is most useful as an early severity signal in the first phase of SJS/TEN management. A higher score can support urgent escalation to an experienced unit, including burn, ICU, dermatology, ophthalmology, and internal medicine collaboration as appropriate to local infrastructure. It can also inform communication about anticipated risk and intensity of monitoring.
The score should not be interpreted in isolation. Clinical judgment remains essential, especially when there are features that can shift risk independent of the seven variables, such as rapid progression of skin detachment, airway compromise, evolving sepsis, hemodynamic instability, or major comorbid disease burden not fully captured by the malignancy variable.
Variable definitions and practical notes
Age: Dichotomized at 40 years in the original model.
Malignancy: Count active or clinically relevant malignant disease at time of assessment.
Heart rate: Use a reliable initial value; persistent tachycardia is more informative than a single transient peak.
Epidermal detachment: Estimate detached or detachable BSA carefully; serial skin exams remain important.
Urea (BUN): Elevated values may reflect renal dysfunction, catabolic stress, or hypovolemia in severe illness.
Glucose: Hyperglycemia may represent stress response, diabetes, or systemic inflammation burden.
Bicarbonate: Low bicarbonate can signal metabolic stress and correlates with severe systemic compromise.
How to use this calculator in workflow
- Calculate SCORTEN at initial evaluation once core labs are available.
- Document total score and component criteria in the admission note.
- Pair the score with organ support needs, fluid balance status, and infection surveillance.
- Repeat risk framing as clinical status evolves, even if the formal score is unchanged.
Interpretation safeguards
- SCORTEN is a prognostic aid, not a directive for withdrawal or limitation of care.
- Predicted mortality reflects population-level risk bands, not certainty for an individual patient.
- Institutional resources and timing of referral can modify observed outcomes.
- Use a multidisciplinary approach for skin, mucosal, ocular, respiratory, renal, and infectious complications.
Calculator disclaimer
This calculator is intended for educational and clinical decision-support purposes. It does not replace specialist assessment, institutional protocols, or real-time reassessment in critically ill patients with SJS/TEN.