Introduction: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are serious, life-threatening skin diseases. Although these diseases are relatively rare, they have high mortality and sequelae rates. Objectives: This study evaluated their potential as biomarkers in the diagnosis of SJS and TEN. Method: We retrospectively analyzed 60 pediatric patients with SJS/TEN who attended our rheumatology clinic from 2017 to 2024. Clinical data and experimental results, plasma cytokin levels, as well as percentages and absolute counts of lymphocytes, were measured in 60 SJS and TEN patients and 20 healthy controls. Results: IL-2, IL-6, and IL-17A levels were elevated in SJS/TEN patients compared to controls. CD19 +/lymphocyte%, CD3 +CD4 +CD8 + lymphocytes were increased, while CD3 +/ , CD3 +, CD3 +CD4 +/lymphocyte%, CD3 +CD4 +, CD3 +CD8 +, and CD3-CD16 + /CD56 + lymphocytes were decreased in SJS/TEN patients. Alkaline phosphatase was negatively correlated with the severity of skin lesions, while CRP and anti-cyclic citrullinated peptide antibody were positively correlated with the severity of skin lesions. Conclusion: IL-2, IL-6, and IL-17A may be potential indicators for the early diagnosis of pSS, together with T-, B-, and NK-cell abnormalities, which may contribute to disease pathogenesis. Larger studies are needed to confirm these findings.