What Causes Burning And Itching In Arms While On Medication For Multiple Sclerosis?

My arms are burning itching feeling upper arms . I use to take Rebif injections for my MS in the areas where it is burning and itchy feeling but it is no rash on my arms . I notice this happen when I take my second dosage of my Tecfedera MS meds that I m currently have been on about a year now . I just start having these symptoms .