Supplementary Material for: A Fatal Case of Infection-Induced Neurofibromatosis Type 1 in an Adult

Background: Neurofibromatosis type 1 (NF1) is an autosomal dominant hereditary tumor disorder caused by mutations in the NF1 gene. It typically manifests in childhood with diverse clinical features, while adult-onset cases are relatively uncommon. In most instances, untreated neurofibromas pose minimal life-threatening risks even in the late stages of disease progression. However, severe multisystem complications may arise, leading to fatal outcomes. Case Description: A 61-year-old male presented with a two-month history of fever, abdominal pain, and bloating, which worsened over four days, accompanied by erythematous skin lesions and blisters. Despite multiple medical consultations and symptomatic treatment, his condition deteriorated, with recurrent fever and diarrhea. Upon admission to the emergency department, rapidly progressing skin lesions were noted. A preliminary diagnosis of intestinal obstruction, sepsis, and fixed drug eruption was considered, and the patient was transferred to the intensive care unit (ICU) for further management. Comprehensive assessments, including thoracoabdominal CT imaging, microbiological testing, and skin lesion biopsy, were performed. Empirical antimicrobial therapy and supportive care were initiated, but microbiological tests remained negative. Histopathological examination of multiple skin biopsies confirmed neurofibromas. The patient experienced progressive enlargement of skin lesions, persistently elevated inflammatory markers, and rapid clinical deterioration, ultimately resulting in death. Conclusion: This case illustrates a rare presentation of adult-onset NF1 with an aggressive disease course and a severe systemic inflammatory response. The rapid progression underscores the underestimated risk of critical complications and mortality in adult patients with NF1.