Decades-delayed onset of subcutaneous granulomata and calcifications from interferon-beta-1a in a patient with multiple sclerosis

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease affecting the central nervous system. Injectable disease-modifying therapies such as interferon-beta have had longstanding and widespread use in MS treatment. We report the case of a 54-year-old woman with relapsing-remitting MS, who developed multiple bilateral subcutaneous granulomata and calcifications on both hips 11 years after a 9-year course of treatment with interferon-beta-1a (IFN-β-1a). We highlight the potential for delayed severe skin responses with subcutaneous IFN-β-1a injections, outline preventative measures, and discuss treatment options for this treatment complication.