Is redness after spider vein removal on the face with a Yag laser normal?

Hello. If the red blotches have shown up only now 3 days after treatment they very well may be unrelated. If something like a blister or other side effect was going to occur, you would most likely see it immediately after treatment. Pictures would help here but in the absence of pictures, go back to your practitioner for an evaluation.

After a variable period of days, the inflammation and redness will subside after treatment with lasers - KTP or Nd YAG. The long pulsed Nd:YAG lasers, such as the CoolTouch Varia is typically gentle. The likelihood of infection is very very small after laser treatment for telangiectasias. If there is a concern for infection, contact the treating physician.Hydrocortisone 1% cream will help reduce the redness and inflammation along with proper hydration with a good moisturizing cream. 

This will get better with time. Wear sunscreen a makeup to hide it until it fades . There is a new cream which is prescription called Mirvaso, which may help.call your doctor- she may samples on the office.