Methotrexate might become the sole treatment option for leukemia following the occurrence of Stevens-Johnson syndrome.

Introduction: Severe cutaneous adverse reactions (SCARs) arising from drug interactions can carry life-threatening implications and result in lasting effects. SCARs can be triggered by various factors, with trimethoprim/sulfamethoxazole identified as a primary culprit. Anticonvulsants and antineoplastic agents have been noted as secondary triggers. Notably, antineoplastics linked to SCARs include immunomodulatory agents. The higher mortality rates among cancer patients with SCARs underscore the significance of comprehending cancer--specific risk factors. Our objective is to present the case of a boy with acute lymphocytic leukemia (ALL) who developed Stevens-Johnson syndrome (SJS) following MTX treatment.

Case report: We present the case of a three-year-old male patient diagnosed with ALL who developed Stevens-Johnson syndrome (SJS) subsequent to the administration of MTX, following the "BFM 2009" protocol. He had undergone intrathecal MTX administration on six previous occasions. Our patient received IVIG at a dose of 2g/kg along with steroids, resulting in partial clinical improvement after 21 days. An innovative protocol was developed, involving IVIG before MTX infusion and dexamethasone before MTXi, with folinic acid rescue. Intravenous immunoglobulin (IVIG) mitigates SJS/TEN via type IV hypersensitivity down-regulation and apoptosis curbing.

Conclusion: As far as we know, the prophylactic use of IVIG to counteract SCARs in a pediatric leukemia patient represents uncharted territory. Moreover, research into the immune system dynamics within these patients and the preservation of indispensable treatments should involve allergist-immunologists as part of the multidisciplinary team attending to neoplastic conditions.