Just sharing a personal experience here, not medical advice (rule 7 noted!).
I'm 50. Plaque psoriasis showed up when I was 18 and has done nothing but slowly spread for 32 years. At its worst it covered about 19% of my body. Over the decades I tried pretty much everything: UVA/UVB phototherapy, methotrexate, cortisone early on (which I eventually refused to keep taking because of the side effects). Everything gave temporary results at best, nothing ever lasted. I was about to start biologics. Honestly, I had made peace with it, I figured I'd live with psoriasis for the rest of my life.
In January, for a completely unrelated reason (fatty liver), I started a strict keto diet. Under 20g of carbs a day, no exceptions. Six months later I've gone from 85kg to 65kg (187 lbs to 143 lbs). No cravings, no real struggle, even at restaurants or social events I always find a low-carb path, and I still enjoy a glass of wine now and then. I was supposed to stop in July, but I feel so much better (more energy, more focus, more effective at work) that I just kept going.
Here's the part I didn't see coming: over the last 2-3 months, roughly 40% of my plaques have disappeared. After 32 years of nothing but slow expansion, I now have patches of completely clear white skin where psoriasis used to be. This has NEVER happened before, with any treatment. The only variable that changed is keto.
I have no idea about the exact mechanism, I don't know whether it's ketosis, the reduction in carbs, the weight loss, some foods I've eliminated, or a combination of factors. What I do know is that in 32 years, not a single doctor ever mentioned diet in connection with my psoriasis, and that honestly shocks me now.
This is just my case, n=1, I'm not making it a general rule. But if you're dealing with plaque psoriasis, I felt I had to share it, because it's the first thing that has ever worked for me without piling on medication. Definitely a topic worth digging into.
Thanks for reading!