RESUMEN
BACKGROUND: Toxic epidermal necrolysis (TEN) is a severe life-threatening drug eruption with rapid evolution. A fast histologic differentiation between TEN and clinically similarly looking staphylococcal scalded skin syndrome is of vital importance for relevant treatment decision. The recently developed ex vivo confocal laser scanning microscopy (CLSM) offers innovative and extremely fast histological visualization of fresh tissue specimens. OBJECTIVE: To assess the diagnostic efficacy of ex vivo CLSM in comparison with standard histopathology for TEN. METHODS: We performed side-by-side comparison of TEN specimens analysed with ex vivo CLSM and haematoxylin and eosin staining. Analysis focused on typical histopathological features of TEN, including epidermal cleavage in the basal layer and confluent epidermal necrosis. We retrospectively assessed the diagnostic performance of ex vivo CLSM for TEN in clinically confirmed cases. RESULTS: We report substantial agreement between ex vivo CLSM and classical histology for the detection of subepidermal cleavage and confluent epidermal necrosis. When considering full-thickness epidermal loss, epidermal cleavage in the basal layer showed the highest diagnostic performance, reaching 87.5% sensitivity and 100% specificity. CONCLUSION: Based on our data, ex vivo CSLM appears as a rapid, resource-optimizing, and reliable approach for morphological TEN emergency screening on fresh skin samples.