What skin involvement percentage defines severe cases of TEN?

Toxic epidermal necrolysis (TEN) is a severe skin reaction characterized by widespread epidermal detachment and significant morbidity and mortality. The severity of TEN is classified based on the percentage of body surface area affected. In this context, cases of TEN are defined as severe when more than 30% of the body surface area is involved.

The rationale behind this threshold is that a greater extent of skin involvement correlates with more severe clinical manifestations, including complications such as fluid loss, infection risk, and systemic complications. The classification aligns with the understanding that extensive skin loss can lead to critical end-organ dysfunction and worsened outcomes, thus definitions in clinical settings use this benchmark to guide treatment decisions and patient management strategies.

In summary, defining severe cases of TEN as those with greater than 30% skin involvement underscores the significant clinical implications and necessitates aggressive management to address the potential for life-threatening complications.