I have the SAME thing as everyone here. I am so sorry!!!! I got my Moderna booster on 12/3 and 11 days later developed an itchy scalp, neck, ears, and they were very hot. I had also gotten another ear piercing on December 7 and thought it was maybe a reaction to that. I took out the piercing in case it was a nickel allergy. Unfortunately, it seems like I am having a reaction to the booster just like everybody else. It’s now been three weeks of itching and dermographia. Unfortunately, I cannot take Allegra and Zyrtec as I am allergic to them and can only take Claritin which I take every morning. I’ve tried Benadryl, I’ve tried Zantac and I put hydrocortisone cream on whatever areas itch. I feel like some days it is getting better though at night, it seems to get worse. The tightness in my chest has dissipated which is good and I keep telling myself that the itching is less each day but I think I’m just being optimistic!! I saw an allergist in January 2021 after I developed COVID arm from my first Moderna vaccine. She said that I am probably allergic to PEG but that I should be fine going forward with vaccine #2. So I got it and was fine outside the normal reaction of fever, aches, headache, chills. Now this after the booster!!