Tecfidera side effects

Hello - first post in a while I’ve been taking tecfidera for around 10months! The last 4 I’ve developed like itching skin - this was originally just located on one leg, but the last few weeks has moved to both hips and back! The itch is like nothing I’ve felt before - it wakes me in the middle of the night, i have an intense Babur big sensation when I try not to itch - mind over matter definitely doesn’t work! I take antihistamines regularly but I have found that now I’m on the highest dose and it isn’t holding it at bay. When it was just on my leg my ms nurse was sure it was the tec (I haven’t told them it has spread- but I will today). Has anyone had similar and can advise on anything that may help? Also just had a tec bloods and everything is in normal ranges and my liver and kidneys are fine - as I did wonder if they weren’t happy and causing the itch! Thanks for any help Nikki x