33M looking for advice

So I'm probably about 90%+ body coverage and sometimes it will scale badly and crack over the course of a few days, which isn't great for obvious reasons. I did methotrexate years ago before biologics were a thing and had throughly exhausted options at the time. Obviously there are other options now, thier starting me on a renal transplant drug to begin with (don't recall the name invercetin or something) and then moving on to I assume biologics. Before I begin all this I'm going to go on a fairly extreme diet (obviously I've been tested for allergens) and was wondering about people's experiences, more specifically non obvious allergens that have cause flare ups etc. I was thinking of going leafy greens, chicken, nuts and seeds. Then slowly reintroducing foods if there is a dramatic effec. Thanks for any advice, also sorry for the long post! Tldr: things that have caused flares