Dermato-neuro syndrome (DNS) is a rare, potentially fatal complication of scleromyxedema which classically presents with a prodrome of flu-like symptoms, and a triad of fever, confusion, and seizures. Intravenous immunoglobulin (IVIG) has become first-line treatment for scleromyxedema and DNS based on limited case reports and case series data that show treatment responses vary among patients. We present a case of DNS occurring shortly after an IVIG infusion, a paradoxical reaction that may complicate clinical decision making.

A 49 year old African American female with scleromyxedema and an IgG λ monoclonal gammopathy presented to the emergency department with fatigue, nausea, and myalgias that began two days after her first IVIG infusion. Within 24 hours of admission, she became acutely altered, disoriented to person, place, and time, and arousable only to painful stimuli. Workup revealed a rapidly rising creatine phosphokinase, leukocytosis, aseptic lymphocytic pleocytosis of the CSF, and signs of moderate encephalopathy on EEG. Extensive infectious, autoimmune, and paraneoplastic evaluations were negative. Her symptoms slowly improved with supportive care over 14 days, though cognitive deficits persisted at nine-month follow-up. The temporal link of IVIG infusion and the exclusion of alternative diagnoses supported a diagnosis of DNS.