IL-6 as a Potential Sensitive Serum Biomarker in Stevens-johnson Syndrome/Toxic Epidermal Necrolysis: Two Case Reports

INTRODUCTION: Interleukin-6 (IL-6) is a pleiotropic cytokine produced by several immunologic cells during inflammatory processes, showing an increased serum value in several autoimmune diseases and infections. Recently, it has been used to evaluate lung involvement in COVID-19 infection, and a specific laboratory test has been developed for such a purpose. We used IL-6 to monitor the evolution of Stevens Johnson Syndrome/Toxic Epidermal Necrolysis in two patients. CASE SUMMARY: We observed two cases of generalized allopurinol-induced adverse cutaneous reactions, including severe hypersensitivity. Serum IL-6 measurement allowed us to evaluate the magnitude of the immune and inflammatory status of patients better than C Reactive Protein (CRP) or White Blood Cell (WBC) count and to evaluate the response to the treatment. CONCLUSION: Although different cytokines and serum markers have been proposed for the diagnosis of severe cutaneous adverse reactions (SCAR) like SJS/TEN, they are still experimental. We were the first to use IL-6 measurement as a helpful biomarker in the diagnosis and therapeutic management.