A 35-year-old man with a 5-day history of fever, oral ulceration, and extensive blistering involving 35% of his body surface area is admitted with suspected toxic epidermal necrolysis. The clinical diagnosis is clear, but the team wants to assess disease severity and predict mortality risk. Which investigation is most appropriate for prognostic stratification?

Explanation

## Prognostic Assessment in TEN ### SCORTEN Score: The Gold Standard for Risk Stratification **Key Point:** SCORTEN (Severity of Illness Score for Toxic Epidermal Necrolysis) is the most validated and widely used prognostic tool in TEN, predicting in-hospital mortality with high accuracy. ### SCORTEN Components | Parameter | Scoring | |-----------|----------| | **Age > 40 years** | 1 point | | **Heart rate > 120 bpm** | 1 point | | **Serum urea > 10 mmol/L (28 mg/dL)** | 1 point | | **Serum glucose > 14 mmol/L (252 mg/dL)** | 1 point | | **Serum bicarbonate < 20 mEq/L** | 1 point | | **BSA detached on day 1 > 10%** | 1 point | ### Mortality Risk Stratification | SCORTEN Score | Predicted Mortality | |---|---| | **0–1** | 3.2% | | **2** | 12.1% | | **3** | 35.3% | | **4** | 58.3% | | **≥ 5** | 90% | **High-Yield:** A SCORTEN score ≥ 3 identifies patients at high risk (>35% mortality) who require intensive management, including transfer to a specialized burn unit or ICU. ### Why SCORTEN is Superior 1. **Prospectively validated:** Developed and validated on large TEN cohorts; widely adopted in international guidelines 2. **Practical:** Uses readily available clinical and laboratory parameters 3. **Early assessment:** Can be calculated on admission (day 1) to guide triage and resource allocation 4. **Reproducible:** Objective criteria with no observer bias 5. **Guides management:** Helps identify candidates for aggressive immunomodulatory therapy (IVIG, systemic corticosteroids) **Clinical Pearl:** SCORTEN should be calculated at admission and repeated during the hospital course to reassess prognosis and adjust management intensity. ### Why Other Investigations Are Not Appropriate for Prognostication - **Skin biopsy:** Confirms diagnosis but does not predict mortality; histological severity does not correlate with clinical outcome - **Serum immunoglobulin levels:** Not validated for prognostic assessment in TEN; immunoglobulin derangements occur but do not predict mortality - **HLA typing:** Identifies genetic predisposition to drug reactions (e.g., HLA-B*5801 with allopurinol) but does not assess current disease severity or prognosis in established TEN