What percentage of body surface area affected defines Toxic Epidermal Necrolysis?

Toxic Epidermal Necrolysis (TEN) is characterized by widespread skin detachment and erosion, often involving a significant portion of the body's surface area. The critical threshold that differentiates TEN from other similar conditions, such as Stevens-Johnson Syndrome (SJS), is often defined in terms of the percentage of body surface area affected. Specifically, TEN is defined as involving greater than 30% of the body surface area. This classification is important as it also correlates with the severity of the condition, prognosis, and the required management strategies.

In contrast, SJS typically affects less than 10% of body surface area, falling into a different category with its own clinical implications. The other ranges mentioned in the choices do not adequately reflect the criteria established for diagnosing TEN. Therefore, identifying greater than 30% of body surface area involvement is pivotal in making an accurate diagnosis and ensuring appropriate treatment.