Cold sores and tysabri


I’ve been on Tysabri for 4 years and love it, no relapses and have been leading a fairly normal life. I had my latest infusion on Monday and woke up yesterday with 2 massive cold sores on my upper lip. Zovirax is not helping - any tips to relieve the awful throbbing blisters?

Also - should I be worried? Not sure if it’s connected to the Tysabri or maybe an after effect of a weekend in the sun- I used to suffer with cold sores a lot before diagnosis.