Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Overlap due to Oral Temozolomide and Cranial Radiotherapy

A 46-year-old man developed Stevens-Johnson syndrome and toxic epidermal necrolysis overlap, with severe localized denudation of the skin on the head and neck, following radiotherapy and oral temozolomide therapy for cranial glioblastoma multiforme. He also had a primary malignant fibrous histiocytoma of the thigh that was amputated 5 years earlier. A rash developed after 7 days of radio- and chemotherapy. It was an extensive maculopapular rash that started over the temporal area of the head and rapidly spread, sparing only the distal limbs. Radiotherapy and temozolomide were stopped on the tenth day but the rash rapidly progressed for the next 4-6 days. Following this, the spread halted and complete recovery was observed within the next 2 weeks. The peculiarity of the presentation in this case was that the brunt of the disease with severe skin denudation was localized to the surrounding areas of cranial radiotherapy. The patient was also receiving oral phenytoin, diclofenac, and parenteral dexamethasone before chemotherapy was started. These medications were continued, even after development of the skin rash, until well after full recovery from the skin lesions. After-critical evaluation of disease onset, progression, and recovery, and their relationship to the introduction and withdrawal of different medicines, it appeared that either temozolomide alone or in combination with radiotherapy most probably triggered the condition.