Thank you so much for the reassurance. It definitely helps to have as many medical professionals weigh in. What exactly is it? Are we allergic to a specific ingredient? Is it our immune system’s response to the mRNA? Will we be ok with other vaccines?

Thanks for the verification, Doc! There's a whole Facebook group of several thousand people who are all talking about this. It's the "Chronic Spontaneous Urticaria After COVID-19 Vaccine Support Group," if you're interested.

I'd never had any significant allergies in adulthood. The first two Moderna vaccine doses only resulted in headaches and the mild "Covid arm" reaction. But two weeks after the booster, I started getting very itchy and experienced dermatographia. It began December 14th and I still have it as of this writing (1/19/22). Mostly annoying so far.

I too am experiencing Dermatographia post Moderna vaccine booster. Received 3rd dose 12/14/22. On 12/25/22 experienced sudden onset of extreme itching, redness, and welts. Finally figured out it was Dermatographia. On
Zyrtec 10mg daily. Seems to keep the extreme itching and welts away, but still experience the Dermatographia.
Is the CDC looking into these cases of Dermatographia post booster?

Thank you for your insights @allergydoc . When you say that it takes 3-4 times normal daily dosing of second generation antihistamines, does that mean I have to take 3 Zyrtec? At once? Every 4 hours? Thank you for your help.