Hi! I also have PA with psoriasis. It's hard for me to give much blanket advice, since I dont know exactly which symptoms your husbands showing at the moment or how severe they are, and my own have fluctuated so much over the last 25 years between debilitating and complete remission, with some coming and going at completely different times.
One of the things I do for myself is something you can't. The high heat and humidity means that going in September simply is not an option for me. I'd love to go that time of year because of the low crownd and prices, frequent
free dining offers,
MNSSHP, and my birthday, but I know my joints won't tolerate it. I don't think I'd even risk it during one of my complete remissions.
When I've got lots of plaques going on, the sun helps, as I'm sure you know. But the dry Western sun helps a lot more than the damp Florida one. (In Vegas and at
Disneyland, my skin cleared 100% even though I wasn't in remission.)
Since my WDW trips were planned far in advance, I worked with my rheumatologist to tweak my medication schedule so I didn't have to take my Humira or Methotrexate while I was on vacation, which was nice.
Last year, I found myself taking a lot of stretch breaks in lines. I'd been having particular trouble with my hands, hips, and lower spine in the year leading up to the trip; the hand exercises in particular were easy to do while waiting. For floor stratches, I'd just find the nearest out-of-the-way sretch of pavement and plop.
If he's taking any pain meds/NSAIDS, I'd advise staying on a strict schedule instead of waiting until it hurts. Set an alarm on your phone or watch because you're at The Distractiest Place on Earth.
Miss some park time for middday pool/bathtub/bed time. You may end up with fewer total hours in the park, but more of them will be actual fun, quality time.
Read the FAQ section about wheelchair/
ECV rental, and keep the info with you when you go. If it turns out he needs to use one, you'll be able to get him one ASAP. Stress that you know he's perfectly capable under normal circumstances, but that a day at WDW is not normal circumstances, and that it's too much for plenty of people without autoimmune diseases.