NAC is a supplement for itching. My dermatologist recommended it. It can be purchased on Amazon and the vegan brand is Nutracost.

Allegra double the recommended dose per my dr

Is NAC - N-Acetylcysteine what you mean by NAC?

Responding to the benedryl and atarax suggestions. Long term use of benedryl. Esp heavy use, which can be a problem bc the body develops a tolerance, is now being shown to have effects on cognition and can be a precursor to early development of problems with memory issues. And atarax if taken in a dose as high as I needed to get the itching to abate also dried my system out significantly. Further aggravating the itching. Adding these comments just to say you may have to try a few different antihistamines with your drs guidance depending on other meds you take or your bodies particular responses to get a good fit. I have Hashimoto’s and A tbi and have to take relevant meds which impact how my body utilizes antihistamines. Likewise bc of lifelong allergies my tolerance for benedryl is so high that I don’t even feel
It if I take a double dose so it is not useful to me like it would be most ppl. And I’d imagine this happens over time with whatever antihistamine we use. I’m trying to add some natural foods and essential oils that are antihistamine in their chemical structure as well. Can’t hurt. .

I use over the counter Benadryl.