Glatiramer Acetate-Induced Serum Sickness.

Multiple sclerosis (MS) is a central nervous system demyelinating disease with a prevalence of approximately 400,000 individuals in the United States. Glatiramer acetate is a frequently prescribed disease-modifying therapy used for the management of relapsing forms of the disease. A 40-year-old woman with relapsing-remitting MS presented with symptomatic concerns of vomiting, fever, diffuse rash, joint and low back pain, and distal lower-limb paresthesia and was subsequently admitted to the hospital for investigation and treatment. She was discharged initially after conservative management with intravenous methylprednisolone and diphenhydramine. She was restarted on glatiramer acetate 3 weeks later and required rehospitalization for similar symptoms 3 days after resumption of the disease-modifying therapy and was diagnosed as having serum sickness.