Prognostic significance of the systemic immune-inflammation index in patients with Steven-Johnson syndrome and toxic epidermal necrolysis

Inflammatory markers such as neutrophil-lymphocyte ratio (NLR) and eosinophil count are known prognostic indicators for the severity of Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN). This study explores the correlation of systemic immune-inflammation index (SII), platelet-lymphocyte ratio (PLR) and NLR with Severity-of-Illness Score for Toxic Epidermal Necrolysis (SCORTEN) and patient outcomes. A retrospective audit of 34 patients with SJS/TEN (25 SJS, 3 SJS/TEN overlap, 6 TEN) was conducted from 2018 to 2022. Mean admission values were SII 1597 (SD 1904), NLR 6.52 (SD 5.99) and PLR 202 (SD 135). Cut-off values for predicting mortality were SII 1238 [area under receiver operating characteristic curve (AUROC) 0.82], NLR 8.32 (AUROC 0.80) and PLR 285 (AUROC 0.78). Multiple logistic regression using a backward stepwise method identified SCORTEN as a significant factor associated with mortality (P = 0.03) after adjusting for SII, NLR and PLR. None of the inflammatory markers significantly predicted mortality, although PLR at admission may be a potential risk factor (P = 0.05).