Stevens–Johnson Syndrome and Toxic Epidermal Necrolysis
Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but life-threatening diseases that affect the skin and mucous membranes. They are usually caused by medications, especially antibiotics, antiepileptic drugs, and pain relievers, although infections can also trigger them. SJS involves less than 10% skin detachment, TEN involves more than 30%, and intermediate cases are called SJS/TEN overlap. The disease develops through a severe immune reaction in which cytotoxic T cells and natural killer cells attack keratinocytes, leading to widespread skin cell death. Several pathways are involved, including granzyme, Fas/FasL, perforin, and inflammatory cytokines such as TNF-α, IL-6, and IFN-γ. Genetic susceptibility also plays an important role, as certain HLA alleles are linked to higher risk in specific populations. Early diagnosis is essential. Biomarkers such as granulysin, RIP3, galectin-7, CCL-27, and IL-15 may help detect the disease and assess severity. Identif...