From all my years here, this is what I've come away with - if a child has Pans/Pandas, there is no "cure" aside from time. As kids mature past puberty, they seem to become less and less sensitive to the impact of a bacterial illness. Some of this is a physical reason - when you're born your thymus is quite large relative to the rest of your body. The thymus is what produces new antibodies against new antigens - it's like the recipe kitchen. As you grow, the thymus starts to shrink, so that by the time you've past puberty, it's the size of a walnut or smaller. This may be because when you're young, your body encounters a lot of infections for the first time and needs an active kitchen to cook up new antibodies to previously unseen bugs. As you age, your immune system has been around the block and the need to a large research kitchen is less. So the aging process is one possible reason that adults are less prone to Pans issues.
The treatments you see discussed here - long term abx, plasmapheresis, IVIG, steroids, supplements, homeschooling, CBT/ERP - are aimed at remissions. Hopefully long term remissions. But nearly all the kids I know who are still kids are still susceptible to a Pans flare if they get sick again, even if they've enjoyed remissions of several years. My kids are in a great spot at the moment - life is exceptionally, joyously normal. But they still have Pans and are still vulnerable. They are healthy but not "cured".
The key to long term remission is identifying the right infection/trigger and treating that properly. In some cases, it's an obvious strep infection and doesn't involve any other issues. In other cases, it can be a chronic infection (long term sinus issues, lyme, mycoplasma) that then weakens the body and other issues move in as well (viruses, chronic mold environment, nutritional deficiencies, yeast). It becomes a complicated, expensive, draining process of peeling an onion - having 20 people toss out ideas to explore and you having to decide which ones to pursue. But even the complicated cases - most parents eventually uncover layer by layer and get their kids back. There's not 100% guarantee. There may be people out there who don't have this experience. But from the people who post here, this is what seems to be true.
I can tell you that having been thru truly awful times, things never got as bad as the early days. As traumatic as things have been, as ugly as some periods were, we never had to go back to the very darkest days, partly because once we had medical support, the element of feeling like you had no one who believed you went away. I could get help with a phone consult or office visit or late night call for a Latitudes BFF. As I learned, I became empowered and that made a lot of difference.
Between the two kids, we have been through steroids, T&A, Pex, IVIG, probably 8 different abx combos, metals chelation, mold removal, pyroluria testing, methylation testing and supplements, vision therapy for convergence insufficiency, treated EBV and done lots of CBT/ERP. We've dealt with vocal and motor tics galore, moderate OCD and all the lovely Pans symptoms thru many, many flares. If someone had told me 5 years ago what was in store, I'd have run away from home.
I don't dare write a sentence that says "Yes, my kids are 100% and are done with this %$#@!" But I can say I've gotten my kids back long enough to get to know the real them and they are awesome and strong and insightful and all our late night CBT sessions and talking thru fears have brought us closer. There have been gifts along the way. I am an entirely different - and hopefully better - mom than I would have been. Right this moment, they are 99 and 100%. That could change. They are not "cured". But they are not permanently damaged, they are happy and life is good.