Track: Case Reports

Abstract:

Nicolau syndrome is a rare and unpredictable injection-site reaction following parenteral drug administration, characterized by severe pain, hemorrhage, ulceration, and potential necrosis. Copaxone (glatiramer acetate) is a mixture of synthetic tetrapeptides used to reduce relapse frequency in relapsing–remitting multiple sclerosis (RRMS). We report a 45-year-old man with longstanding RRMS that is well controlled on subcutaneous Copaxone injection for over 10 years. The patient denies any history of injection-site reactions except occasional mild redness at the injection site. Following his most recent injection into the left posterior arm, he experienced no immediate pain or rash. However, after 36 hours, a violaceous plaque evolved rapidly over the following 12 hours with associated sharp pains at the site and distal to the eruption on the arm down to the elbow. He also noted intermittent tingling in the ipsilateral fingers. On examination, there was a well-demarcated erythematous to violaceous plaque on the left arm. Punch biopsy revealed widespread intravascular fibrin thrombi with associated dermal vessel and tissue necrosis; the overlying epidermis was largely necrotic. Most dermal vessels contained fibrin clots without evidence of vasculitis. Given the acute presentation, histopathologic findings, and absence of vasculitis, a clinicopathologic diagnosis of Nicolau syndrome was made. The pathogenesis of Nicolau syndrome remains unclear, and there is no standardized treatment. This case highlights Nicolau syndrome as a rare but serious injection-site complication of glatiramer acetate, underscoring the importance of clinician awareness and prompt recognition to enable timely, supportive management and reduce morbidity.