There aren't too many noticeable positives of enduring a flare-up that lasts a full month or more. I am sure that there are probably a few, but not many come to mind immediately.
With that said, there is ONE benefit that quite nice:
The longer I am stuck at home during a flare, the more money I save!!
I can't really go anywhere, so I save on gas money.
I can't really eat a lot and my appetite decreases drastically, so I save on grocery money as well as money I might usually spend on lunches/dinners out.
It's pretty impossible to go out shopping, so I am not tempted by impulse purchases, new clothing, etc...
I usually remain in sweatpants and big t-shirts or sweaters, and do not change outfits multiple times a day like I normally do. This helps me save money on laundry.
I wear my glasses far more often than my contacts when I feel that terrible, so I don't have to order contacts as frequently, which saves me money on optical expenses.
I also tend to use less makeup, perfume, nail polish, and (subsequently) less makeup remover, not to mention using far less hair product. That way, my beauty products do not run out as quickly, so I save money on replenishing them.
Without being constantly out and about, and because I wind up sleeping for a majority of the time, I use way less data - so I save on my monthly cell phone bill.
Go figure, right?
Long flare-ups:
Bad for the body, good for the wallet!