Bullous pemphigoid as an injection site reaction of glatiramer acetate

Glatiramer acetate (GA) is one of the well-tolerated disease-modifying therapeutic options, which is commonly administered subcutaneously in patients with multiple sclerosis (MS). The current study aimed at defining a bullous pemphigoid (BP) skin reaction in a patient with MS receiving treatment with GA. A 29-year-old women with MS, receiving GA treatment within the past nine months, November 11, 2018, was admitted to our MS clinic due to itching skin eruptions at the site of injection. Her disease was started at February 12, 2017 with left optic neuritis; and because of six periventricular and eleven juxtacortical brain magnetic resonance imaging (MRI) lesions without any enhancement, lumbar puncture was done for her. Due to positive cerebrospinal fluid (CSF) oligoclonal band, MS was diagnosed for her. At that time, she refused to start disease modifying treatment. GA was started 9 months before admission for her.  After dermatologic consultation, the dermatologist defined the lesions as fluid-filled and blistering at the site of injection without mucosal involvement (Figure 1).   Figure 1. Large, fluid-filled blisters   Timeline: Skin lesions appeared exactly at the GA injection site.