I appreciate your mentioning L-histidine. It is an amino acid which has been shown to improve the barrier function of skin per this article and others (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5634381/) and I will look to take it now.

My GD has been aggressive in the past few weeks, so I have been on the search for a reason. I have been thinking GD might be associated with Herpes. Not a Herpes infection but related in that it shares some of the behavior of Herpes. It can wax and wane. It moves up and down my body, but does not affect the skin where I recently had shingles, suggesting that it, too, resides in the spine and not in the skin. I have been looking into essential oils or any dietary influence, both positive and negative for Herpes. I tried nigella sativa, which I am taking now. It smells like volatile cleaning fluid and I have to take with honey. It did not have any effect on my GD, but it did bring down my blood pressure which is normally 100/60, but had shot up since the GD. Then I saw that the amino acid Arginine can feed Herpes, and Lysine can counteract the Arginine and that people use Lysine to prevent Herpes recurrence. The collagen peptides I'm taking has 3 x more Arginine than Lysine. In addition, my plant based diet with lots of nuts and seeds, and no animal products, is very high in Arginine. So now I am taking Lysine, 3 grams/day - and my GD has faded and I slept super soundly for the past two nights. I was still itchy and used Ben-Gay at night before going to bed, but didn't wake up once scratching (it had been happening every two hours before.) So I would say, I am optimistic, but the jury still out on that one. I have been using large amounts of cilantro in my daily smoothie since the beginning of Feb - it hasn't changed a thing for me, but I continue to use.

I do believe that anything that improves the barrier function of my skin is something I will try because if nothing else, it will make me look younger. Yay!